Stupid, stupid name, but I guess they were running out of cats.
But the under-the-cover improvements alone have me all excited.
And one of the user-visible features that I'm going make great use of is being able to AirPlay an extra display to my AppleTV.
Other random musings:
iCloud keychain is likely to replace 1PasswordiWork in the browser will be fantastically usefulMaps! Finally!Compressed memory instead of disk-paging is going to be brilliant
I still don't think I'll ever be able to say "OS X Mavericks" with a straight face