I remember that thread, mouser. I'm with you, for journals and magazines, the letter size is pretty ideal. I've been reading on 4" androids, ipads, asus transformer, and the surface pro. The one I like the best is the surface pro. Now, for journals and magazines, it's still too small. Most people will say I'm crazy, but it is. It's a big screen, great resolution, great everything, but for that kind of stuff it is still too small. You really need 8.5x11 viewable.
For comic books, it's a little better, since comic books are shorter and narrower...however, even comic books feel just a tad scrunched.
Sounds like the issue is that if you make the tablet any bigger, it's not going to be comfortable to carry and use for other things. I don't know. If the new surface was letter size, I would jump on that.