Well, if one of your complaints or defense mechanisms against 29"ers was that there are not enough good tire choices, you are going to be having alot harder time convincing yourself now. In addition to Panaracer, (Rampage 29"er), Geax, WTB, (Weir Wolf LT), Bontrager, (Dry X Tubeless Ready), Specialized, and Kenda, who are all releasing new model 29"er tires, you will have Michelin added to the list.
The "XC-AT" tire in 29"er size is to be introduced soon. Dubbed as a long wearing, ample sized ( 2.1"), and decent all around tread, the XC-AT is also said to shed mud pretty well. As far as casing size goes, Michelins are said to be pretty good sized in comparison to the competition, so that's a good thing.
I think it's safe to say that if you can't find a decent 29"er tire, you aren't looking........at least in the near future. It's true, alot of these tires are not out there.......yet! When they do become available, then one of the last detriments to going to a 29"er will have been swept away. As it is, some retailers are already taking pre-orders for this Michelin tire and it's to be available soon. I think 2007 will be the year that tire problems for 29"ers will cease to be an issue.
Now, if only Hutchinson would come out with that rumoured Python 29"er tire!
Update: Now hearing that the Python will be introduced in January in the 29"er size!