Maybe Miyamoto doesn't consider this a revision. I don't think the XL is meant to replace the existing 3DS like DS Lite replaced the original.
Yes. I mean, I'm going to buy the 3DS XL, it's a no brainer for me, my interests, and my playing habits, but the size really, really cuts into its portability. For the longest time, I've carried around both my 3DS (in my pocket) and my XL (in my bag) and 99 times out of 100, I'm busting out my 3DS. It just makes it easier. There's a lot of people, maybe most, for whom that will be a #1 priority. Look at the DSi XL. How many people who had a DS went to the XL? Show of hands, please? [crickets chirp] I thought so.
At the same time, I love my XL, and I'm thrilled about this. I think a lot of people complain about how the XL's screens are bigger but don't add resolution, and so the picture would, could, and in a way does look worse. But for anyone who actually owned an XL, yes, all 5 of you, you love it, love the huge size of the screens, and can never go back to your DSi or DS lite.
I know the paragraph above seems directly at odds with the one preceding, but really, it comes down to the tradeoff-- screen size vs. portability. Good points on both sides, and you've just got to choose what's more important for you. Of course, since save data is stored on the game cartridge and not the SD card...well, you may be able to enjoy both.