Can you folks just not let this stupid concept go already?!?
Why would you want a smaller screen, less storage space, lower data throughput performance, and an external box optical drive you'd have to remember to take with you "just in case"? I'm sorry, but this whole notion is just so counter-intuitive and retarded. Apple should be learning lessons from Sony on this one. It's just a problematic solution looking for a problem to solve.
I would want the smaller screen, etc., because hauling around a full-size laptop is a pain. A fully-functional computer that fits in my purse would be a godsend, because I would take it with me everywhere.
As for the optical drive, not only would I not tote one around "just in case", I wouldn't bother with owning one, period. With today's network speeds, plastic optical disks are going the way of the floppy drive. I'd rather not bother with it. I'll download any apps I need, and use wireless network storage for my files.
For 90 percent of my computing needs, an iPod Touch with a full-size (or nearly full-size) keyboard would be adequate. Make it run a full version of OS X and support 3rd party apps, and there's the other 10 percent right there.
Take that concept, make the screen *just barely* big & hi-res enough to browse without using the "zoom" feature, and it's the Best Laptop Ever as far as I'm concerned.