I think, to be honest, we're all in agreement that Deidara's toast. It's common knowledge that supporting characters in shounen mass-market action series only get character development just before they die. I mean, look as Asuma- the bit where he coached Naruto on wind chakra use was probably the most significant thing he's ever done, and right after that he croaked.
What I found rather more interesting was the revelation that Deidara was recruited specifically to take Orochimaru's place (apparent from Sasori's comment about having to be paired with Deidara). This means that either Orochmaru left VERY early in the formation of Akatzuki (even before they managed to make a full circle of 10 members) or they lost another unknown member as well. Deidara wasn't given Orochimaru's ring (he kept it) so it had to belong to someone first.
Also remember that when they were extracting the Shukaku from Gaara, someone (I don't remember who and can't be bothered checking) commented that it takes longer without Orochimaru, which means Orochimaru was present for at least one of the extractions (most likely the previous one since this appears to have been the first time it was mentioned). Either they were capturing jinchuuriki even before their team was complete, or... hey hang on, this just plain doesn't add up!
Or maybe Orochimaru was just moved from partnering with Sasori to someone else BEFORE he left Akatsuki and Deidara was brought in while Orochimaru was still there?