I foresee a lot of trouble as a MBP user with no other Apple products (MBP=work machine). Interoperability with Android phones is already sucky and they seem to bundle their product line even more.

Siri for MBP will be annoying, hope it can be disabled completely...which of course won't stop my co-workers from using it all day :(

It also sounds like there will be a few new attack vectors. The log in when close by sounds like a pretty horrible idea and I have a feeling the copy/paste feature will turn out to cause some issues as well.