having a glossy screen increases the contrast of the screen. Thus printing out images will have considerably different colours than the ones you see on your screen. So if you work with photo editing of some sort then the antiglare should be your way to go, so much less hassle to get the colours to be the same (screen-print).
Im a student, i got myself the hi-res antiglare back in april when it was released. I dont regret it at all. All my friends who have the previous gen. MBP are totally jealous, of both the higher resolution and the antiglare. My school only uses apples, so every teacher has a 13" macbook pro, even they say that the glossy screen p***es them off

The director got himself a antiglare when he saw mine
I was at a study course, after lessons i was outside all the time with my MBP, it was really sunny, and even then i had my brightness set to 50% and saw everything perfectly, my friends were at 100% and reflections still annoying.
I prefer the Hi-Res antiglare over the glossy my far.
When buying my MBP i thought of it like this. Ill get a MBP that fits my needs, but ill choose all those options which i cant upgrade myself in a year or two. So i went with the i7, Hi-Res antiglare, left the rest at stock. That way soon i can upgrade the RAM to 8 gigs and fit a SSD. All cheaper now already. As i do 3D work on the side the Hi-Res gets another plus point there, so much nicer if u can work with more pixels.
Looks wise: Sometimes i lean to how the glossy screen looks but then the antiglare resembles the last Gen (non unibody) MBP. Which i liked more anyway
MY TIP, get the antiglare, its worth it