Here's the newest scoop from Kristin at E! Online, and notice her wording on the last question/answer. Me thinks someone will be leaving someone at the altar...

Is Grey's going to suffer now that the spinoff is on the way? Will the writers be pulling double duty?
Grey's writer Mark Wilding tells me the spinoff would probably be staffing "new writers," rather than cannibalizing the Grey's staff. And great news for Buffy fans, it looks like former BTVS boss Marti Noxon has been tapped to run the spinoff.
This Gizzie thing is really pissing me off. Tell me George will come clean with Callie this week.
Sorry, but their secret will stay hidden from Callie for at least a few more weeks, though she knows something's not right.
Are Cristina and Burke really going to get married?
They really are going to make it to the altar in the season finale, and the wedding will be everything Cristina did not want, as evidenced by that hilarious pic above! She'll wear a big dress, have bridesmaids and be writing her own vows. So much for the justice of the peace.