It finally arrived on Wednesday, too late to get the three free Doors tracks, but that's no problem since those tracks were also part of the Best of the Doors collection that I was going to buy anyway (and, in fact, have already bought).
The first change is the new introductory sequence. The previous two both had a cartoonish, silly segment with a band playing on a vehicle as it hurtles over various obstacles. In Rock Band 2, to emphasize the "battle of the bands" aspect added to that version, it was two bands struggling with one another in that situation. All that is gone, replaced with a very slick montage of images depicting a band gathering, going to a venue in a big city, and playing, interspersed. All of it is in quick shots in artistic lighting so I can't be totally sure if some of it is real photography rather than CGI. It's very well done and definitely conveys more of a sense of "serious music" than the previous versions, befitting the game's evolution.
The change from RB1 to RB2 didn't add a lot of new functionality, apart from that Battle of the Bands thing which I never used; its main virtue was a big new playlist of songs. RB3, by contrast, adds a huge amount of gameplay improvements, but it doesn't disappoint on the songs either. Of any rhythm game's built-in playlist, none has ever had so many songs I know and like. Chief amongst them are a bunch of Doors songs, and Radar Love by Golden Earring, which I have been lobbying for since I first started playing Rock Band. And having played it, I still think it's one of the best songs for Rock Band ever.
The biggest new feature everyone's talking about is keyboards, and we've had a keyboard sitting around for almost two weeks taunting us. I only played keyboards for a few songs and found it surprisingly different. Yes, you're essentially doing the same thing as on guitar, and yet somehow the differences add up to more than I expected, and it'll take more adjusting than I expected. A lot of songs that don't actually have a real keyboard part still work by using keyboards for things like horn sections, which opens up a ton more songs. I wonder if people who actually play keyboards will find this more comfortable than do guitar players find rhythm game guitars; it's less wholly different, but that might not be better. I expect that keyboards will become more differentiated from guitar more in harder modes where you start doing more chords.
The other big change is pro mode. In this, it's good to be a drummer, because all the songs I've accumulated from RB1, RB2, track packs, and downloads, all have pro mode support already in them; they've been encoding songs for pro drums since day one. Not so everything else: you can only do pro mode guitars on the new songs, and for keyboards, on older songs you can't even play keyboards, though you can use the keyboard to play bass or guitar parts. (Pro mode and keyboard add0ons for selected older songs will be sold eventually.) Not sure if pro mode changes vocals and if so if the old songs need recoding.
When it comes to playing drums, pro mode doesn't make that big a change; you just need to play the cymbals separately from the pads, so you have essentially eight inputs instead of five. I've been playing that way, at least to my best ability to predict which notes were cymbals and which were tom-toms, since I got the cymbal set, so I'm finding myself able to get good scores in pro mode immediately. Admittedly I haven't tried yet on harder songs or harder play modes.
On guitar, bass, and keyboard, pro mode will be a lot bigger a change. In a way it'll be relearning from scratch. (In fact, I'm tempted to learn keyboard in pro mode right off, so as to avoid that retraining. Though I probably won't do keyboard much anyway.) This is going to be most pronounced on guitar, where they've invented a notation for guitar chords that is reportedly a bit weird and hard to get used to. (My You Rock Guitar is not yet working with pro mode, so I haven't seen it yet, though it's widely speculated that we should be seeing a firmware update eventually.)
These changes have taken all the spotlight, and really reinvigorated the game, at a time when a lot of people wondered if there was enough new to add to these games. In fact, they could have made Rock Band 3 just add keyboards and would have sold like hotcakes, then saved pro mode for RB4, and still had enough new stuff they put into RB3 to make an RB5. I don't know what they're going to do for RB4 and on, in fact. It'll be hard to imagine what more there is to do.
Those other changes, though, are also quite impressive. First, there's a new career track system that is maybe a little harder to get started on, but perhaps more compelling. Again, you form a band and track it through its career, and part of that is getting better modes of transportation so you can go to more venues. But more is changed than stayed the same. For one, cash is eliminated entirely; you earn new gear and clothes directly. So are the cities: you go from town to town, but they're not named as specific cities.
What's more important is what's added. First, in addition to just playing a song for as high a score as you can get, you're also playing for some secondary goal which varies from one venue to another. Perhaps you'll get better results by using overdrive a lot, or having longer streaks, or having more high accuracy sections. Your progress depends both on these and your overall score. Progress gets you clothes, gear, and access to more venues. It also earns lots of trophies, with which the game is provided in great quantity. All in all, it means each venue isn't just the same thing as the previous.
The interface is also changed in some very subtle yet well-designed ways. First, each person has his own menu to do some things like choose their character or set their options, which they can do independently of everyone else or whatever's going on on the screen. Second, people can join your band at any time, even in the middle of a song; instead of having a bunch of different bands, you have one band which is made of whoever happens to be playing at the moment. As always, the game fills out your band with stock characters, which it calls "session musicians," but in a very nice new feature, you get to pick which ones it should use, and it is smart enough to rotate out males and females so the right gender is on vocals (if vocals aren't being handled by a player).
It's really amazing how many improvements they've fit into a game that seemed like it already had almost everything. They left no stone unturned when looking for things that could have been done better. Veteran Rock Band players should expect to spend a little time reacclimating to menus and how careers work and such, but will be able to jump into playing immediately. So it's the best of all worlds.