Interesting. Blackwell says it isn't routine, but to announce something significant at Gusev.

His comments:

"Based on what I'm hearing, I would advise everyone to tune in to this news conference. This is not the run-of-the-mill MER briefing but, from what I undestand, big news from Gusev and the Columbia Hills. "

and later clarification,

"what I meant by "big news" is on a similar scale of importance of, say, what Opportunity found in Eagle Crater at Meridiani Planum. In other words, something related to the story of liquid water at Gusev Crater, which heretofore has taken a definite back seat to the discoveries made at Meridiani Planum. What I'm not predicting, however, is anything related to "life on Mars," "ancient martian civilizations," etc. "

Wonder what it could be. More official follow-up to the earlier announcement about the salts in the soil?

Hard to see what other major thing they've found, given how they've mostly just been travelling. Not a lot of measurements done with the instruments on the arm (usually you see images of it when they are using it), and not many MI images lately. Perhaps some interesting findings in the Pancam or TES spectra? They did take a full-filter mosaic a few days ago, and presumably did TES readings too.

The only thing that especially caught my eye lately was this rock (center left) in the Sol 159 images, which does seem to be weathering in an odd way -- as if it is wearing away in layers, and with some odd little protrusions along the edges of each layer. Some other little ones at upper center. Yes, made me think of the Meridiani rocks, but until getting more and closer views I'd chalk it up to a quirk of erosion of a piece of shattered basalt.

Something similar in this sub-frame from Sol 158 (up and left from center) , or a different angle on the same rock. They did do a full filter set on this one if someone wants to play with color.

Intriguing, but you'd think they'd have poked around at those rocks a lot more before announcing anything if that's what's excited them.

Anyway, my bet would be that it's not as significant as Blackwell suggests, maybe just announcing they see some interesting outcrops and have a plan to reach them. But I sure hope I'm wrong!