Possibly not Gal; he gives her his sonic screwdriver but its never stated that its the same one used by the tenth doctor (I think). Speaking of the eleventh doctor and River Song, not sure if its episode four, five, or six of this season but he is supposed to meet her at some point.
Given that his current companion may make the choice to leave the doctor, we may in fact be seeing Song as his companion. (I doubt it, but you never know.)
It got destroyed in episode one, but he built a new one at the end of the episode. There is nothing to say that the sonic screwdriver he gave River Song in the Library was the same one - and since both episodes were written by Steven Moffat I assume he's allowed for it somewhere along the line.
BUT, just look at River's driver
And look at Ten's
Ten recognized it as his own because it;s obviously the same one (or same model) highly modified.
Now, look at Eleven's
Totally different. Not sure I even like it, it;s very aggressive looking
As for the doc himself, Tennant is an insanely hard act to follow. The man redefined the role, for me at least.
That said, I didn't like Tennant at first either. We'll see
At least he's not traveling with Donna again.
I miss Martha Jones. I was disappointed when she didn't end up joining Torchwood (not that there's much left of that after Children of Earth)
Already available for pre-order from Big Bad Toystore, by the way