According to MJ's Big Blog (who has the sources listed over there for where she got it from), the boys are performing tonight instead of the girls because Crystal Bowersox is ill. They've never done this before and people have been sick in past seasons. Looks like the powers that be do not want to see Crystal get booted! Manipulation at its finest...

http://mjsbigblog.com/

• RE: Top 10 Boys performing tonight!,Snidget, 04:58 PM, 03-02-10
• RE: Top 10 Boys performing tonight!,zazzy, 05:43 PM, 03-02-10
• Still unclear if Crystal can perform tonight,Snidget, 04:52 PM, 03-03-10
  • RE: Still unclear if Crystal can perform tonight,Belle Book, 05:22 PM, 03-03-10

Joe's Place has some of the tweet and a link to the EW.com site that seems to be confirming this as well.

Hmmm, maybe they wanted to give Crystal the pimp spot?

Wonder if the guys are bummed that they had one less day to prepare.

Wonder if Ryan will a) explain the change at all, b) mention that some of the girls are ill, or c) specifically mention Crystal.

For more info on previous seasons' semifinals pimp spots info and how it turned out for the season--check the pimp spot thread.

LAST EDITED ON 03-03-10 AT 04:53 PM (EST)

Ryan twittered they are having a meeting about what to do.

ETA recent twitter

In a meeting now about it. Hang tight! RT @Oc_Danielle: Is #CrystalBowersox going to be on tonight #Idle @RyanSeacrest? about 1 hours ago via UberTwitter

It would be so sad if she couldn't perform! She wasn't my favorite but I don't like seeing anyone go out because of an illness!