When the new season started, reviews on Behind the Sofa were mixed, skewing towards the negative. Now, after The Girl In The Fireplace, the Who-related Livejournals have got in on the backlash as well.
I for one thought Stephen Moffat and Euros Lyn delivered the goods. Yes, there were dodgy moments - it's Doctor Who! The aliens are going to have the weapons that are most likely to stop them right in the middle of their control center. No, it wasn't up there with the very best of the previous season. Most of the previous season wasn't up there with the very best of the previous season. But we got another tightly-directed, no-filler episode with suspense, humour and great visuals, most of which made narrative sense.
A lot of the criticism focused on the Doctor's apparent decision to leave the companions behind to save the Madame de Pompadour. I think it's been established by now, as part of the new character, that the 10th Doctor's ethical compass is broken*), but even if that weren't the case, it wouldn't be him abandoning his friends to save one person, it would be him sacrificing his own life and that of the companions, who know the risk involved, to maintain the integrity of all of Earth's timeline past the 1720s. It's at the very least defensible, and the Doctor would be in a position to weigh the consequences better than anyone else.
It's probably in the nature of fan communities to turn against that which they are fans of. But if it goes on I'll just leave those communities behind.
*) In The Christmas Invasion, the Prime Minister's decision to blow up the aliens is, given what we know about them, the best course of action for Earth and for any of the worlds these barbarians might visit next. It's a decision the PM doesn't take lightly and it's likely to be a blight on her soul for the rest of her life, but the Doctor's reaction doesn't make sense. Even Mahatma Gandhi would have pushed the red button on those guys. In New Earth the Doctor happens to be in the right, but only because the entire scenario is skewed in favour of him being right. Without the clones turning out to be sentient after all, the entire ethical basis for his position collapses under his feet. In both cases, the Doctor takes his visceral disgust with the actions of other people for sound moral judgment.