Lack of time definitely influences my play, as does the fact that I don't have buddies come over to play on a daily basis. But, not sure if my tastes have really changed.
But, I've always been a person who liked a wide variety of games. When I was younger, I played a lot more sports games (pretty much every 2 years, got a new game in the 4 major sports), and put 100 hours easy into each of them. But, back then my buddies and I played these continuously.
During college, had time to play, but my gaming buddies all went to different schools, and I went to a commuter school, so no dorms for big gaming parties. During this time, I got heavily into RPG's, etc.
Now, with a family and working, less time for gaming. I'm definitely into shorter games now. Doesn't mean I won't crack out a 50 hour game, but it has to be excellent to hold my attention, since I have to play it over a month. Now, it almost feels like I have ADD gaming, tons of games, but it takes a special one to really grab my attention.