The House of M #1 variant cover by Joe Mad! did indeed come out today and retailers only got a single copy of it! There are dozens of them on eBay as your reading this that are going for $30+ dollars. If you haven't already you should check your local comic shop for this cover if it isn't already gone. Over at Joemadfan.com Nathen bought two copies (one from two comic stores) and said he paid between $20 and $30 for each of them so this cover comes at kind of a hefty price.
I'm checking my local shop tomorrow so hopefully I will get my hands on it so I can scan the cover for the site. Check back tomorrow for the update.