If the Ultraportable MacBook Pro does exist—despite the specs that were "leaked" being too ridiculous to actually be true—how big would it be? Well, judging from both the 1280x800 resolution in both the MacBook and the UP MacBook, the screen ratios should be pretty similar.
Add in the "less than 1-inch thick" spec, and the fact that it's ultra-portable, which puts it in line with laptops like the Sony VAIO VGN-TXN15P/W, the dimensions should be quite a bit smaller than even the regular MacBooks. In fact, it's may be as much smaller than the MacBook than the MacBook is compared to the MacBook Pro.
Of course, this is all conjecture, since we don't believe there's going to be an Ultraportable MacBook coming out any time soon with those ridiculous specs.
Thanks to Sizeasy