I recently spoke to a Samsung rep (Samsung's website live chat) and with a Samsung rep (in person). Both said:
"it will be updated, at least to Android 4.3, but we cannot tell you when".
So I'm pretty sure we are getting 4.3 at some point. Heck, if the Note 2 and S III got it, it's only reasonable that our Note 10.1 gets it. It was the flagship tablet of its (short) time, such as the Note 2 and S III being flagships/high-end. Everyone's been saying that Samsung won't update it to force us go for the Note 10.1 2014 edition, so why did the Note 2 and Galaxy S III get the update (ok, ok, Galaxy Gear blabla)? Wouldn't they force you to go for a Note 3 and Galaxy S IV? You get my point.
So, be prepared to wait (wait... wait... wai...), and official news about the updates *cough kitkat* are coming.
My guess is: Android 4.3 and no Android 4.4, unfortunately but thankfully.