The pace right now is stable and quite impressive given the current development teams and resources. Also, they aren't pushing the barriers with the new back to back games thing, they're actually creating new barriers, so the outlook gets changed. Like everyone is going to be totally hyped until next month, and still hyped until the English version is out. Like many pointed out the lag between DPPt games, the only reason they may have to do this is having something for us to be hyped over XD
No really, I don't think at this rate they're going too fast. Until now no major Pokémon game has been a flop, and the speculation about and around X&Y is probably proof it's not going to be. What we need is change and new features, along with a genuinely new feel. They're doing that quite well, yes?
Since the main games aren't the only games being worked on considering Spinoffs, I'm pretty sure the Pokémon Franchise is used to handling games at this pace without making it feel rushed. It all depends on the reception, to know how rushed it was in reality.
I also seemed to personally feel that they're starting to run a bit faster now, but the only reason B2W2 was released so fast is because of the good linkage to the original versions, so we don't have to worry.