Glossy yes, Glassy no.
I did have a unibody 15" MBP for about a week, initially i loved the screen when i used it at home, but once i took it into the office it annoyed the crap out of me. It just did not play nice with a light source above/behind you.
For me it is not a glossy v matte issue, its a Glass issues. As someone has raised, its not glossy, its glassy. I also have a MBA, that has a glossy screen, and i do not mind it at all. In fact I prefer it to my 17" matte, but its the glassy I could not stand.
Go into an apple store and have a look at a MBA (Glossy), 17" Glassy and a 17" Matte. This will give you a good idea of the differences. I suspect that you will be shocked by how nice the MBA screen is, and that is glossy. Also if possible turn off each one and look at the screen with the unit shut down, this really shows you how reflective the glassy is.
Though in the end, its personal choice. The good thing about apple is you have 14 days to decide, heck give it a test run. If its not for you, return it.