That Start menu...
...has been variously broken (depending on what sort of account you use to log on with) in every build so far. The same for search and for Spartan. For those playing along at home, try logging in as the Administrator, or as the domain's Administrator. In 10049, the breakage is slightly different in each case.
Naturally I've reported this and I'm assuming that someone is keeping count over there so it will all be fixed in the final release, but I'm intrigued to know just how they are managing such fine-grained damage.