I just wanted to add my own little piece to something that RicOlie_2 already gave an admirable response to:

Verboten, about your objection to Palpatine's question to Anakin....

Palpatine's question to Anakin is just part of his manipulation of Anakin to turn him against the Jedi Order. Repeatedly in "Revenge of the Sith," Palpatine does this through two methods (which occasionally overlap):

1) destroy Anakin's trust in the Jedi by making him think that they are purposely lying to him and that they purposely aren't telling him certain things they know

2) make Anakin think that Palpatine knows things which the Jedi don't (both knowledge of a factual nature and also knowledge about how to do certain important things with the Force).

His question to Anakin about Darth Plagueis is just part of this manipulation and seduction. It could be like #2 above, in which case he's not implying the Jedi know about Plagueis, he's just showing off his superior knowledge to Anakin. But either way, I think you're reading a little too much into dialogue that is intended to be manipulative and deceptive.

I actually don't think that the possibility of the Jedi knowing about Plagueis necessarily has to be seen as so far fetched anyway, but even if it is far fetched, Palpatine's question doesn't have to mean that they do know.

I hate "Revenge of the Sith," so I'm not defending it. I just think it should be hated for the right reasons.