I see that I'm not necessarily in the minority, at least not here at SHH. Other folks are apprehensive of Moriarty's return, with most not even believing it will be him and that it will instead be a new "protege" taking over for him or some kind of plan concocted by Morairty before his death.
I'll admit that I'm not fond of either of those two scenarios. It's also a bit counterproductive for the series in general, since Moriarty killing himself to throw off Holmes was a pretty brilliant twist. Then again, if Sherlock was able to figure out a way to convincingly fake his own death, it stands to reason that Moriarty would do the same. Still, a body must have been recovered since everyone believes Moriarty to be dead, so one has to wonder how they'd "bring him back" without it having been a twin or something completely contrived.
Another reason I'm not too excited about Moriarty's imminent return is that it feels a bit soon in terms of the chronology of the series (even though it's already been years). By that I mean that an epic return or final game with Moriarty would have been perfect for a final season/series of 'Sherlock'. I mean, what better way to end it all than to have Sherlock face off against his nemesis one last time? But since Moffat has previously said they have both the fourth and fifth series mapped out, I imagine it will be really hard for them to have to try and top another Moriarty season AGAIN.