I recently brewed a Kolsch using White Labs yeast and did not detect any sulfur. I fermented at 62 degrees, and the beer came through with a nice fresh well balanced taste with a clean finish. I am drinking a glass of it right now, yum.
On the other hand, I have an ESB fermenting at the moment using White Labs Burton Ale Yeast and it smells really bad, full of swamp gas. It is at 64 degrees at the moment.
I'm sure someone with far more knowledge than I will be along here in a little while, but I think the type of yeast and the fermentation temperature have a lot to do with it. I would expect more fruity aromas out of a warmer fermentation, and some yeasts just give off that foul sulfur aroma during fermentation.
I have never had the sulfur carry through to the finished product when I have been patient and let it age before drinking.
Tap 1 - Kolsch
Tap 2 - Hefeweizen
Primary - ESB
Secondary - Empty
Next up - a Pilsner or another Kolsch to get me through the summer.