I don't know if it's a good time or a bad time to play them - Norwich were deadly against Blackburn, and though they only drew with Sheffield Wednesday, Wednesday are a good side with promotion ambitions of their own. They've a couple of injuries and are quite light up front right now though, so probably as good a time as any to play them, though I've predicted a defeat.
I don't know how Newcastle and their fans have reacted to two defeats in two - it could either be that a negativity will permeate amongst the squad that makes them vulnerable, or they'll be frustrated yet focused and give someone a right tonking (I predict that they'll record a 6-0 or similar against someone at some point this season - though I'd like to think not against us!).
Villa - it could depend on how they do over the next two games. 3-0 over Rotherham was a good result, but at the same time I don't think it's unfair to say that they're likely to be amongst to poorest sides in the division and many people tip them to finally get relegated. Huddersfield are many people's dark horses and Derby are perennial contenders at this level, so I suspect that they could well only earn a point or two from those games and come to Ashton Gate pretty dejected. The opposite could be true if they get two wins though...
Being conservative, I'll predict just one point (a draw with Villa), but plenty of scope and opportunity to improve on that. I think even four points should be considered a good return if we can achieve it.