Newest gameplay trailer with updated UI (NEW!)
New freestyle guitar solo feature explained/shown in action (NEW!)
1 hour Gameplay stream (pre-alpha version)

See bottom of the post for current song list
Things we know: (Red = new info, updated 7/13)
-Playstation 4 & Xbox One
-October 2015 release planned
-1080p & 60fps
-RB4 will support lead guitar, bass guitar, drums, pro drums and vocals (and harmonies) only. It will not support pro guitar/bass or keys/pro keys.
-PS3 hardware will work on the PS4 version using a dongle, and a "low cost" adapter will be sold that allows you to use the 360 instruments on the Xbox One version
-New hardware is being made (obviously)
-Harmonix does not intend to create a sequel model out of this game; rather, they hope to update it over the course of the generation with new features & songs
-There is a focus on improvisation/personal touches/"coloring outside the lines" added to the gameplay, for example:
-The drummer can now count the band in at the start of the song
-Open drum fills have been replaced with randomized fills (the game will choose a random fill from a pool for you to play, based on the song's genre and difficulty). This is confirmed compatible with legacy songs
-Freeform vocal melodies: Vocalists are judged less harshly for improvisation; allowed to get creative rather than recreating the original track 1:1. This is scored separately from accurate singing.
-An explanation of freestyle guitar solos (There is a video of them in action above)
-Vocal harmonies have been added to all the legacy songs (note: this is a community effort made official, which is super neat!)
-New feature: Gigs allow you to play a set of songs with your band, voting on the next ones & interacting with the crowd in the dead time between songs
-DLC will be compatible across generations (PS3>PS4), but not across consoles (PS3>Xbone)
-Transferred DLC/Disc imports will not cost anything extra
-Not all DLC/Disc imports will be available day one (likely due to licensing issues); these will be rolled out with time
-RB3's on-disc music can't be imported at the moment, but it's possible this could be added down the line
-New DLC for RB4 will be released (obviously)
-Compatible with the Rock Band Stage Kit (yes, really)

Songs:
.38 Special - "Caught Up In You"
4 Non Blondes - "What's Up?"
Aerosmith - "Toys in the Attic"
Arctic Monkeys - "Arabella"
Avenged Sevenfold - "Hail to the King"
Benjamin Booker - "Violent Shiver"
The Black Keys - "Fever"
The Both - "Milwaukee"
Brad Paisley ft. Keith Urban - "Start A Band"
Brandi Carlile - "Mainstream Kid"
Cake - "Short Skirt/Long Jacket"
The Cure - "Friday I'm In Love"
Dark Wheels - "V-Bomb"
Disturbed - "Prayer"
Dream Theater - "Metropolis Part 1 - The Miracle and the Sleeper"
Duck & Cover - "Knock 'Em Down"
Eddie Japan - "Albert"
Elvis Presley - "Suspicious Minds"
Fall Out Boy - "Centuries"
Fleetwood Mac - "You Make Loving Fun"
Foo Fighters - "The Feast and the Famine"
Gary Clark Jr. - "Ain't Messin' Round"
Gin Blossoms - "Follow You Down"
Grouplove - "Tongue Tied"
Halestorm - "I Miss the Misery"
Heart - "Kick It Out"
Heaven's s**** - "I Am Electric"
Imagine Dragons - "I Bet My Life"
Jack White - "Lazaretto"
Jeff Allen - "Recession"
Johnny Blazes and the Pretty Boys - "Cold Clear Light"
Judas Priest - "Halls of Valhalla"
The Killers - "Somebody Told Me"
Lightning Bolt - "Dream Genie"
Little Big Town - "Little White Church"
Live - "All Over You"
Lucius - "Turn It Around"
Lynyrd Skynyrd - "That Smell"
Mark Ronson feat. Bruno Mars - "Uptown Funk"
The Mighty Mighty Bosstones - "The Impression That I Get"
Mumford & Sons - "The Wolf"
The Outfield - "Your Love"
Ozzy Osbourne - "Miracle Man"
Paramore - "Still Into You"
The Protomen - "Light Up The Night"
Queens of the Stone Age - "My God Is The Sun"
R.E.M. - "The One I Love"
Rick Derringer - "Rock and Roll, Hoochie Koo"
Rush - "A Passage to Bangkok"
Scandal - "The Warrior"
Scorpions - "No One Like You"
Slydigs - "Light the Fuse"
Soul Remnants - "Dead Black (Heart of Ice)"
Soundgarden - "Superunknown"
Spin Doctors - "Little Miss Can't Be Wrong"
St. Vincent - "Birth In Reverse"
System of a Down - "Spiders"
U2 - "Cedarwood Road" (NEW!)
U2 - "I Will Follow" (NEW!)
Tijuana Sweetheart - "Pistol Whipped"
Van Halen - "Panama"
Van Morrison - "Brown Eyed Girl"
The Warning - "Free Falling"
White Denim - "At Night In Dreams"
The Who - "The Seeker"

Pre-order for 30 free Harmonix songs, pre-order at Amazon for an additional 4 free songs

Can't wait for the nerd band videos to come back again.
\0/

Nice to see the game coming back

I call Bass!

Drums

Or lead but I'm better at drums

MG band when?

will they release the kazoo yet
i would be f*** boss at that

HYPE AS f***
I could play almost every song on expert guitar so I call that for MG Band
Also vocal harmonies actually are confirmed

I could 100% most songs on Xtar :^)

Where's the confirmation on harmonies? I'm sure they're in, just haven't seen it anywhere

thx. added some info to the OP

This bit is interesting:
All things considered though RB3's setlist was pretty weak so I'm not especially disappointed

Also this
Learning from Guitar Hero I see

yesssss

so hype!!!
i was thinking the other day that i wouldn't be seeing another rockband or guitar hero release, so this is a nice surprise

Ikr. I love these games. So happy this will be a thing.

Song request form here:
http://www.harmonixmusic.com/games/rock-band/request/

Harmonix is pretty good about getting fan favorite songs, so feel free to stick some of your faves in.
(Be smart - put in The Protomen's Light Up the Night. For me)

So you know, you're allowed to put in as many requests as you like.
(I put in Hatredcopter.)

The problem is that you can't put in a general artist request

I'm good with just about any Dethklok. King Crimson doesn't really have one song to rally behind && push forward. I'd like to see Tool but I never bothered to listen to them so I don't know any of their songs

Hopefully they track artist stats too, independent of song requests

Also: Vote Babymetal