Just a stab in the dark, but has it been suggested yet that the almighty incorruptible Jean-Luc Picard might just get sent to the big Vineyard in the sky? I hate speculation just as much as the next guy, but Picard has pretty much been the standard of modern Trek for just about 21 years now. He's got to get killed at SOME point.
As long as there's a TNG series, I'm sure there'll be Picard.
I mean, who'd take over command if he was killed? Worf? Remember that DS9 episode where Sisko said that Worf would probably never get his own command (after he bungled a mission to rescue Dax)?