Funny, I'm seeing the same thing. Before updating to 2.0, my 32gb touch was able to identify the location of my office (in Center City Philadelphia) within a block. After the update, Google maps just gives me the spinning wheel forever. Before the update, if it couldn't figure out my location, it would time out after a minute or so with a message "Your location could not be determined". That never seems to happen in the 2.0 software. Yes, I have enabled location services.
It is a little annoying in some applications, "MyWeather" for example. It defaults to the weather in your current location, and it seems to consider that to be the most recent place where it was able to locate me. So every time I run that app, it assumes I'm still somewhere I was two weeks ago when location services actually worked!