From Rockbandaide.com:
 

• Jefferson Airplane – Somebody to Love
• Blood, Sweat & Tears – Spinning Wheel
• Santana – Black Magic Woman *
• DragonForce – Through the Fire and Flames *
• DragonForce – Operation Ground and Pound

* Denotes Pro-Guitar/Bass chart availability for an additional $.99

The first three tracks are part of the “Days of Peace” Pack, available for $5.49 (440 MSP).

And with Through the Fire and Flames having a Pro Guitar upgrade, I see many pro guitars being tossed around.

Holy Batman. We has no chance - not even the guys from DragonForce can play their own songs properly :P 
 
Still, kind of awesome to see TtFaF make the jump. But if they were gonna pick some silly impossible song for all those beginner guitarists, they could have been a little less obvious ;)
 
     

Nah.  Rock Band's April Fools usually ends up being some song that you're not sure if you really want, and it's free. 
 
I probably won't get any of these.  Don't care for the pro upgrades (don't have a pro guitar yet anyway), and the other songs, while classic, I'm just not sure about spending the points on.

its like the Jimmy Buffett / Disturbed week all over again except this time the good songs aren't the metal ones.

Holy shit I am definitely getting that pack. There's some good stuff in there.

Somebody to Love will be played non stop. I love that song.

next Friday is April Fools Day, that would probably be when they make their faux setlist 

"Somebody to Love" is a must for any Jim Carrey fan. That one's gotta be great fun at parties, thanks to The Cable Guy. Also, Black Magic Woman's probably one of my top 10 favorite songs ever. I want to stop buying DLC, but if they keep releasing songs like this, I might not be able to resist the urge.

Somebody to Love and Black Magic Woman (love the GH3 chart), so excited. About time they got some Santana in there.

I'm getting these... 
 
 

• Jefferson Airplane – Somebody to Love
• Santana – Black Magic Woman *

" its like the Jimmy Buffett / Disturbed week all over again except this time the good songs aren't the metal ones. "

" @JJWeatherman: I feel like HMX is trolling their hardcore userbase by releasing a pro guitar chart for through the fire and flames. "

" @JJWeatherman: The pro guitar chart cannot be played at regular speed. "

This is like the time they put out a Jimmy Buffett pack that was 10 times more interesting and fun to play than the Disturbed songs they put out the same week.

" @Zidd said:

" its like the Jimmy Buffett / Disturbed week all over again except this time the good songs aren't the metal ones. "

The good songs were never the metal ones. 

The Days of Peace pack was disappointing on guitar when I played it this morning.  The mix on "Somebody To Love" makes it really hard to hear what your actually playing.  The rhythm guitar is turned way up, so the lead gets buried.  On "Spinning Wheel," you're playing the horns pretty much the whole song, which is just weird.  "Black Magic Woman" is the best of the three, but they didn't include "Gypsy Queen" along with it, which they did in GH3's cover.  BTW, I had no idea that song was originally done by Fleetwood Mac.