Prometheus is getting a whole lot of attention in the news today.

Despite protests, NASA continues nuclear use -- Note that the MER heaters are not part of Prometheus.

NASA Chief Touts Nuclear-Powered Craft -- WAPO requires registration, so I didn't read this one.

Nuclear power in NASA's future? -- Generally positive, favoring the possibilities while only mentioning in passing the Cassini protests (for "balance", presumably).

NASA moots nuke spaceships -- A more detailed version of the preceding article.
"There is no way NASA can say for certain that something is 100 per cent safe." No kidding? Can you say driving to 7-11 for a jug of milk is "100 per cent safe"? Oops, better stay home...assuming that's a "100 per cent safe" alternative...

O'Keefe says future spacecraft may be powered with nuclear energy -- Basically the same article as the preceding link.

NASA chief touts nuclear power -- See above, same article.

Future spacecraft may use N-power -- (sigh) More of the same. My, we have some lazy journalism going on here. I have to wonder where the original article came from.