It would be awesome but
Nell can't be Masaki! I see the resemblance now but like orin noted, the chins are different. And just like with Miyako and Orihime's chins, I don't think Kubo does stuff like that without wanting a clear difference.
But it would be so cool if it were true. It would explain Nel's overprotectiveness of Ichigo (all sexual innuendo be damned!). Anway, the speculation on German forums is that Maski = Nel, a friend said, and I was oooh, I wonder if my friend brightredglow who speculated seconds after the raw was out started the whole thing. I didn't see the resemblance until today, really.
Anyway, early spoiler: Nel was the THIRD ESPADA.
Nnoitra, it was nice to know ya.
As for wacko theories, I'm still holding out for Szayel being a Quincy. Apparently we get a little of that fight this time ... or at least just Pesh, and I love Pesh so alright, I won't fault you yet Kubo-san. But could the pace get ANY slower? :-(