I feel the same way -- I feel like Kubo couldn't have possibly given Ulquiorra so much importance and depth (and we haven't even gotten to his backstory yet, which will be very telling as well) if he hadn't intended him to mean something in the larger scheme of the story.

I have a hard time believing Orihime will fight Ulquiorra. She's shown a backbone when it comes to him, but she's also showed concern (when he got trapped in the caja negacion) over his well-being, too.

I think if Ulquiorra falls, if Shirosaki somehow manages to come forth and beat the crap out of him, that Orihime will step up to save him/heal him. It's just this gut feeling I have. (Oh, and wouldn't Ichigo be pissed.)