Is my front sprocket suppose to wiggle? It's on but it's got side to side movement.

The gear is only held on by a C clip. Mine has some slop too, but beware that i had to replace a shaft on a dirt bike I owned because over time it wore the slpines to the point where I didn't feel comfortable with the amount of play it had.

Only a very minute amount. What year is your GS? See Kerry's post here (soon to be edited to go directly to post): http://gstwins.com/forum/viewtopic.php?p=84036#84036
and
http://www.gstwins.com/forum/viewtopic.php?p=57768#57768
(Haha! It worked! Thanks Kerry and Rema!)

I had the same thing and was concerned.  It's normal.  My KLR250 has the same amount of play.
Mike

Also, related: http://gstwins.com/forum/viewtopic.php?t=12488&highlight=front+sprocket+wear+splines