I bet it's going to be the same form-factor as the MacBook Air (but taller), with the optical drive optional (but with USB ports compatible with the MacBook Air drive), to keep its cost even lower (and allow for a smaller size).
If the computer is targeted at switchers, then they should be able to use the optical drive of their Windows PC (same thing as the MacBook Air), and for only 99$ more you can get a double-layer DVD burner to put on top of it.
Let's just hope it will at least get the same X3100 as the MacBook. A maximum of 4GB would be nice (though a minimum of 2GB max is a must). If space is cramped it could even have 2GB soldered on the motherboard like the MacBook Air. I'm betting it will use a 1.8" drive, too. Apple is planning for the future, and the future is SSD. Why not change the form-factor right now?
One thing I would like is an eSATA port, but in reality I'm just hoping they keep FireWire 400 on it (at least for mini-DV owners, for iMovie).
On the other hand, I'd much rather have a more powerful Mac mini, same form-factor as the

TV and Time Capsule (taller, I wouldn't mind), with a 3.5" drive in it, memory slots (4GB max), decent GPU with dedicated RAM, FireWire 800.
