I have a few I'm interested in, but I'd be up for riding just about anything.
The one you just missed at CM and one at Boyne last week (Burton, K2 and Rome)... then there's the Burton one at Boyne in February... unfortunately that's all that I really hear about in MI. There's a huge demo/trade show the week prior to this Burton thing in February but it's industry/invite only.
Marhar Snowboards out of Grand Rapids will probably do a few demo days (just them) at Cannonsburg and Caberfae. They might make it back to Mt. Holly later in the winter like they did last year, too. I haven't heard anything definitive yet but I'd be surprised if they don't do at least a few.
The only other company aside from Marhar (which is local) and Burton (which is huge) that puts much presence around MI resorts is Rome but I don't think they do any demos, mostly they just sponsor rail jams and other events.
Any particular boards you're interested in, or did you just want to get a chance to try out as many as you can?