Steve,
I agree it does sound like it might fit the bill. Clay's son seems to go really good on one too. I know Jeff has always said he wanted a modern long stroke motor and this may be it. I never saw one, but did see an older 450 up close at the Rattlesnake enduro a few years ago. They seem to have very few issues, you get the impression that R&D and prototype testing were very well done and the production bikes are ready to go with no BS. I'd like to see how the parts distribution takes shape before any consideration though.
That new Yamaha 250f is an interesting bike. I love the compact layout, no pipe exposed, and short muffler. Not much to break in the rocks. Even the seat height spec is an inch lower than the '13. Gained four lbs over the '13, from EFI no doubt, but thats a good thing if they did not cut corners elsewhere. I was checking out a new '13, they are light and ergos fit me very well. I'm going to watch this one close, let someone else try one in the woods first, but its very attractive.