Oh, that's my bad. Didn't realize you were on a different topic.
I haven't heard much in the way of interest from American teams yet, just because the invitation is there doesn't mean they necessarily have to accept it, but I feel that Zandvoort would be a good showing for Cadillac. Would be nice to see the Ferrari and Effort Porsche join in (or even better if one of the top GTA teams decided to fly over *cough* Momo Ferrari *cough*)
Speaking of PWC and going back to the Lexus topic: It could be interesting to see if Lexus would be accepted into the slightly-more-lax championship to further develop their car as well as their American connections. It's more of a GT3 car than the Acura is, and could add appeal to the series.
I for one have always been a fan of fringe-GT3 cars, though.