Originally Posted by
MushroomBomb
I'm not sure any Doctor in the future will be able to sustain any more than three of four series at most (including Matt Smith). And I'm worried that the limitation lies in the companions rather than the doctor. To me, while it is without a shadow of a doubt my favourite TV-series, the companions just seem to get a bit stuck in a rut quickly. I was half-way bored with Rose already when the Doctor regenerated and by the end of series 2 I was glad to see her go, just because she no longer brought anything new to the show, in any way.
Luckily, this is being shaken up a bit with the new series, I'm looking forward to a proper male companion. I am also very much a fan of the Rory/Amy relationship and, to an extent, the Doctor/Amy relationship. The only thing I'm worried about in terms of companions right now is that Steven Moffat starts reusing River Song for everything. She's a fascinating character, but I imagine she'd get boring really fast if given a semi-permanent role. Showing up in 2-3 stories per series is just fine for her.
Mind you, this is just my personal opinion. Nothing I can really back up with fact, it's just how I feel about it all.