I also wonder why the upsurge now. Is the new Iraqi government better at "extracting" information?

It's possible, seeing as how many countries aren't as squimish about using force to get information. However, it's perhaps more likely that the average Iraqi is more willing to cooperate with his government than with ours. This is essential - the Iraqis have to claim ownership of their country and stand against those who're killing innocent civilians (and no, dog breath, that isn't the US). In that vein, there was the report earlier this week of vigilante groups threatening the foreign terrorists, including Zarqawi by name:

"We swear to Allah that we have started preparing ... to capture [Zarqawi] and his allies or kill them and present them as gift to our people... This is the last warning. If you don't stop, we will do to you what the coalition forces have failed to do."