Consoles are, at least for me, lousy for reading text. They have all the disadvantages of a computer with none of the advantages (high resolution, etc.). And you can't sit in a comfortable chair and read however you feel like; you're tethered to that TV. Even reading the news on my Wii feels kind of awkward.
That said, I was surprised to find out how good an e-reader my Nintendo DS Lite is. I got the ebook collection for it pretty much on a whim ... I just had to see ... and while I certainly wouldn't want it as my primary reading device, it's nice to be able to pull it out of my pocket (it can go more places because it occupies such a small pocket) and read when I couldn't easily cart my 505 with me. I would love a program that would let me load my own books on there for easy portable reading -- I think they're missing a big bet.
Like that art studio program ... great, it will teach you to draw. Looks interesting, but not interesting enough to buy. But if it would let you transfer your sketches to your computer, I'd be on my way to GameStop, because I'm forever sketching things out on napkins and the like (yes, really!) and I'd love to have a way of doing that on my DS and using the sketches later on. Everyone else who needs to sketch things at random times would probably want one as well.
Nintendo, I think, can't get past the idea of the DS as a toy for children. Sure, it's a great toy (the calendar can make me grow old, but it can't make me grow up) but it has the potential to do things far beyond that.
And I think consoles suffer from the same problem. They're great as dedicated game computers, but they could do a lot more. However, the people calling the shots -- Sony, Microsoft, and Nintendo -- have set up their developers' pricing and approval structure so that only games, and specifically games for their target market, can be produced. That's too bad, because there are some possibilities for quite a lot of other things.
I don't think large-screen ebooks, though, are likely to be one of those things. Now, if it was more of a coffee table book kind of thing, that might be cool on a HDTV, but you're still running into the resolution problem.
As it stands, I'll take my 505, my DS, and my computer for reading books, and reserve my consoles for playing games.