that's what this blogger says happened -
http://healingiraq.blogspot.com/I couldn't copy and paste a quote from the site, but two entries a little bit down the page talk about these demonstrations.
Baghdad Burning mentioned demonstrations, but only mentioned them as containing lots of communists and being frightening to her.
The above blogger says the demonstration (after the capture of Saddam) contained a variety of people from various factions.
There is also streaming video from Reuters in the entry.
Also, there is a page where there is a vote for "best Iraqi blog" via a link at Baghdad Burning. I went to the link and found about a half dozen Iraqi blogs there.
It's really good to read what those people are saying about what's going on in their country, and their reactions to the capture of Saddam and the presence of the U.S.