I have been hesitant, very hesitant to try T/S lenses on the G1 as the focusing (with a T/S) lens is very very difficult.
Anyway, I tried one today (a 24mm experimental T/S lens). Here is a sample (this is a crop).
I can confirm again that IME, a Nikon D40x works better when it comes to focusing and getting the shot as I want it. This sample shot is a fluke.