[andie74]

We know that a key leader of his network was captured on December 31, so this is not exactly implausible.

[InfraRed]

We know that a key leader of his network was captured on December 31, so this is not exactly implausible.

Precisely. Per CNN...

Fadil Hussain Ahmed al-Kurdi, 26, was responsible for "facilitating communications between al Qaeda and the al-Zarqawi terror networks as well as coordinating the movement of terrorists in and out of Iraq," according to the statement.

A bin Laden capture may not be far behind...

[ProudVet77]

I think what you are seeing is that Google can't keep all their servers with the same content. I've tried it on a 32 server webfarm and it was tough enough, I suspect they have close to 500 servers. Each time you refresh the google news search you go to a different server at their end so you get different results sometimes.
However, your observation of the 31 Dec date is interesting, I've seen it too. But I've also seen wrong timestamps on Google before.