@Patrick D. - As Jeff says, it would be VERY hard to have a WordPress related domain if you couldn't include WP in the domain! However, as they have stated on their site, they are happy with that just not the full!

I personally don't think they could enforce people like that is because it could be something completely UNRELATED to WordPress, afterall, it's just 2 letters!

Just my honest opinion though, each to their own! :)

Thanks
Mark