Fallout New Vegas is pretty much a guaranteed success, at least as far as score and initial sales go.
It will be interested seeing how the game will be remembered though.
I'm pretty sure reviewers were all 'yay' about KOTOR2 when it came out, yet now it's mainly remembered for its cut content.
Anyway, I have faith in Josh, going by the way he answers here on the forums, on Formsprings etc., he seems to have his heart in the right place.
Not that I don't like Avellone, but Planescape : Torment suffered much less from its mediocre gameplay because combat wasn't the focus, and KOTOR II had a lot of painful combat sequence that basically amounted to me spamming Force Lightning.
Won't comment on Alpha Protocol, but looking at the reviews, it seems that all Avellone's titles, with all their differences, are characterized by similar problems and strengths.