10-0-11-0-00 x 02 from Galactic Center

First of all, while I love Rose and am happy to see that she's coming back for an appearance in the 50th, I really hope that Clara is not related to her. Especially the theory that she is the daughter or Rose and Ten-two. The show is called "Doctor Who", not "The Doctor and Rose". I won't stand for it!

I like the Emperor Dalek theory (Clara is the shards of the Emperor scattered through time by Rose/Bad Wolf) but this doesn't really jive with the Doctor having watched Clara grow up on earth.

I think what's happening here is that we've met her out of order...

The Clara that's traveling with the Doctor right now is regular human female Clara Oswald (Oswald for the win - Oswin) augmented by, not one, but two trips into the Great Intelligence's mainframe (or whatever) courtesy of the spoonheads. This is the same intellect that we see her display in the Asylum, and may also expalin why she can read Gallifreyan. And this is also the beginning of her becoming a weapon against the Daleks once the lock is opened on the time war using the Doctor's real name.