Once, many years ago, I left a class at college because I had finished reading a book (think it was the 3rd book in the Laurrel K hamilton Anita Blake series) to quickly drive over to a book store, buy the 4th book, and then return to class (so I could keep reading the series during class hehe).
I never once left a class or missed a class because of a video game, although I am most certainly a hard core video game player. I have spent more time playing video games then anything else in my life in fact, even reading or sleeping (didn't sleep much when I was younger).
Video games though never got in my way, or hurt my grades (4.0 for my AA, 3.98 for my BA and currently a 3.97 for my masters with 2 classes left).
What is more, a large percentage of my fellow students also played video games. Muds, which were text based early versions of current MMORPGs like world of warcraft) used to be played almost entirely by college students and while some students did end up dropping out because of the games, or at least received lower grades, the large majority did just fine.
Video games help spark creativity, they help motivate students (something fun they enjoy doing that uses the mind) and depending on the video game they improve problem solving skills as well. I'd say you are usually WAY better off playing a video game then watching TV, and quite often you are better off playing one they reading a book (depends on the book of course...and the video game for that matter).
MMORPG's of course can be addicting and take over someones life, but I think that is a totally different story. Video games as a hobby certainly do not make it less likely someone will go, or graduate, from college.