Over the course of one news report, the info goes from "Emma Watson will NOT star in the final pair of Potter flicks" to "Well, actually, we don’t know for sure." Sounds like it’s contract renegotiation time, kiddies!
Some sources indicate that Ms. Watson wants to branch out and try different roles, and subsequent reports dictate that the gal IS expected to sign a new contract before too long. (It’s all just too confusing to contemplate, isn’t it?)
Seems that Watson’s co-stars, Daniel Radcliffe and Rupert Grint, HAVE signed contracts for Potters Part 6 and 7, but that Watson has yet to seal the deal, hence all the "will she or won’t she" speculation. Apparently Warner Bros. is "extremely confident" that Ms. Watson will return to end the series … which means they probably made her (and her parents) a very sweet offer.
Source: Dark Horizons