Hopefully. I've been hoping they'd do a multiple doctor show. I think "The Four Doctors" is still open. They could have 8-11 for the show...or even crazier, maybe the 6 doctors! Maybe they could have a whole slew of them for something like that.
Probably wouldn't happen, but that would be fun if they did.
Some of them are just too old. But Tennant will do it - he does anything the BBC asks - and I think Eccleston can be persuaded despite his claims to the contrary. Dunno about McGann, but he still does a lot of audio stuff, so he's clearly amenable.