Rock Band 2 is the perfection to Rock Band 1′s innovation, according to the Harmonix development plan. Even the start menu is way more hardcore, with a snarly white tiger and slithering snakes.

We’ve been hearing Rock Band 2 tidbits for a while now–84 songs on the Rock Band 2 disc, 500 total in the playlist by the holidays (“The Moby Dick of playlists,” says PR Coordinator John Drake, who took the stage to demonstrate for us), the first Guns ‘n Roses track in 14 years (“But is it a good song?” — “That’s a great follow-up question!” Drake teased), full compatibility for downloadables and your original Rock Band instruments. The focus of today’s demo was showing off new modes, but we also got a quick strum on the Sunburst guitar.

First up, Quickplay has been revamped to look like the Rock Band store. You’ll see the whole list on the right, with the selected track’s artist, album, year, and difficulty ratings for all the instruments on the left. Holding down the sort button pops up a menu of headers (genre, for instance) which make navigation much easier, a must, since the track list is only getting longer.

The new set list creation feature makes Quickplay a lot more seamless, since you can fit “more [songs] than you could play without going to the bathroom” and play them without always going back to the menu. Any of the sorting headers can be selected to play all the songs in that cateogry, so if you have an urge to play all the A songs, or have a Bowie marathon, or throw an 80s night party, it’s easy to set up.

World Tour (solo or band) has also been upgraded with new cities and venues, and– the best part– online bands. You can also hire staff for your tour this time around, which sort of act like accessories in an RPG–they’ll boost certain aspects of your score, whether it’s how much money you make or how many fans you win. Your Mom is the stand-by, but you can also hire a street team, a (drunk) publicist, an intern, or a tattoo artist.

Distinct from the regular Tour Mode is Tour Challenge, which is pure tiered progression with a lot of different ways to proceed. It’s designed to give the best experience possible for each instrument, so you’re not stuck stumming the same three notes on a stellar drum track. Events are unlocked as you go based on difficulty, but will also appear when you acquire new DLC.

Probably the most exciting feature for the true rock band maniacs is Battle of the Bands. This mode pits your band against first your local friend list scene, and then the world, as you compete in new battles everyday. Yes, so if you can’t pull ahead of the pack in a battle to master a certain album, maybe you can beat them at this new song, or at abstaining from star power, or at any of the daily new challenges that the designers devise.

Bands from all over the world put up scores during the limited time (the one they showed us had 13 days to go) and if you get passed up, the game sends notification or you can even get e-mails via rockband.com.

Drummers will be stoked for the included drum lessons–a whole mode just to teach you proper vocabulary, beats, tempos, and fills, while those who have partied too hard to play Rock Band anymore can let their characters jam on their own in Jukebox mode. Lots of new features that are worth exploring.

My exploration began today when I briefly wielded the Sunburst stand-alone guitar. Unfortunately I was too pussy-footed to land the premium drum set, but it seems a lot sturdier than the pack-in, and of course, as we already know, it can function as an actual electronic drum set (if you buy the add-on module and an amp).

For my part, on the guitar, I felt like the strum bar was a compromise between the clicking (which I prefer) of Guitar Hero 3 and the super-padded original Rock Band version. We played Mountain Song by Jane’s Addiction, and got to hear the Rock Band fellows do Cheap Trick’s “Hello There.”

Whether you can afford all the new instruments or not, the disc, at least, is pretty much mandatory for Rock Band players. We’re hoping to get some more time with it on the show floor, and will update this post with drum impressions if we get the shot.