Please don't fret! There is still time for Steven Moffat to plan to include all the surviving Doctor Whos-or companions- in next year's Anniversary Special.
Their not knowing anything about it doesn't mean they won't be approached in time.
According to Matt Smith, even he does not know yet what the Moff is planning to do. But he has faith he is planning something big.
In 1983, when "The Five Doctors" was being prepared, they did not even get the filming started until early that year, with only some odd months to go before the episode was to debut.
So if that is any indication,there IS still time to get a script together and a cast and make a special worth remembering!
Keep the faith!
Prydonian, a loyal establishment.