A friend of mine was concerned about preordering his Xbox 360, saying that GameStop was told by Microsoft to stop taking preorders. That Microsoft had already presold every thing they could build. I called my local GameStop, and sure enough... no love.
But wait! Not so fast there, smokey. I called EBgames, and the guy said "Sure, we're taking preorders. Filled up the first batch, but you should be in the next batch. And heck, with the amount of preorders we have, Microsoft could even increase our first delivery, so you might be lucky." Woo!
So I dropped by the store today, forked over my $50 deposit, and got my preorder for the premium system. If you want a system this year, then I'd highly recommend that you get yourself to a store and preorder. Call ahead to your local game store to double-check. Generally, you also want to avoid the web-based preorders — they're bundling a bunch of games and other stuff which you may not want. Brick & mortar stores will do barebones systems.
The countdown begins...
Update: yes, I know GameStop and EBgames are the same company. Why they have different policies... well, they'll probably be managed quite separately for a while.