MacRumors.com

BoyGeniusReport claims that MacBook Airs have arrived at retail stores and will be placed on display starting Tuesday (update: maybe Wednesday).

Product banners and visuals will go up on Monday night in all Apple stores for the official “launch” on Tuesday, and the Genius Bar employees get their official training tomorrow.
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UPDATE: Looks like it might be Wednesday now!

Steve Jobs had originally announced that the MacBook Air would be available starting 2 weeks after their announcement, which brings us to this Tuesday -- making this seemingly quite a likely claim. However, we have not heard independent confirmation, and BoyGeniusReport's reliability has been mixed.

Readers who have their MacBook Airs on pre-order are waiting in this discussion thread, ready to post photos when their MacBook Airs arrive. Meanwhile, for those waiting for the MacBook Pro updates, we've heard whispers about their imminent release.