David is officially confirmed for next year's specials. After that, there has been no announcement about whether he is continuing with the role, but I have seen no indications that he is not.
According to some sources (a few of which are, shall we say, less than reliable), he has been offered a £1.5 million ($3 million) deal to do the next series.
I check his website
here daily for any official news.
Unless it is on there, or the BBC make an official statement, don't worry.
DON'T BELIEVE ANYTHING UNTIL OFFICIALLY CONFIRMED!!!