Right, I've now seen them both.
The first time I went into my (temporarily) local Apple Store they only had the 15" and low(er) res 17"ers. My initial impression was "wow" when I saw the 15". The thing is bright and uniformly lit. I didn't notice any of the 'yellow tint' complaints, but I was only in an Apple Store so the lightings not great.
Yesterday I went back to the same store and they had a high res 17" in. These things are fricking great. Running Aperture at such levels of detail on a laptop is a strange, but great, feeling. I had no complaints regarding the size of the text. To be honest, without thinking about it, I would not have even notice the text was smaller than normal! The screen itself is very good quality - I noticed no fading at the corners or anything like that. It's also bright, though maybe not as bright as the 15", but certainly better than the old models I think.
All in all, after messing around with the high res 17" for half an hour, when I went back to look at the 15" my initial reaction was "Whoah...that all looks a bit big". Kinda like switching your monitor back to 800x600 or 640x400 or something! In other words, you get used to such a high resolution quite quickly, so I wouldn't worry about things being too small (unless you don't have good eyesight, in which case you'll never get used to it I guess).
So, the difficulty is, two future laptop norms are incorporated into two different machines. Sooner or later or laptops will have LED screens, but also they will have high DPIs like the 17". As we can't have both in the same machine, the question is which one is of the most practical use for you.