yep, id save up for a iMac, or wait to see if they put a decent gaphics chip in the iBook replacements
The rumors I heard was the iBook replacement (I have heard it will be called MacBook no Pro on the end) will get the ATI X1300 which is an excellent value end card, so I would highly reccomend waiting to see what they do with them instead of grabing a Mini for SL.
Now with that said I do have a friend that runs SL on a GMA950 Windows Box and it plays just not well, he gets choppy frame rates and takes a log time to rez. So it should play if you get one just not great.