According to all the news reports, 25-30,000 people attended last night's massive rally demanding: “State Commission of Inquiry Now!”

It was sponsored by a coalition of groups.
Tens of thousands gathered Saturday night in Rabin Square in Tel Aviv to support a call for a state investigation into the war.
Speakers at the protest were to include former education minister Yossi Sarid (Meretz) and former defense minister Moshe Arens (Likud).

"We must do soul-searching, examine ourselves and 'purify the camp,'" Movement for Quality Government Chairman Eliad Shraga told the protesters, setting the tone for a series of angry speakers.

MQG Chairman Eliad Shraga appealed to the all of the nation to join the rally, which contained people from all sides of the political spectrum. One of the speakers at the rally was former Meretz chairman and minister Yossi Sarid. His presence, said Shraga, was an answer to "all those people (primarily from the Peace Now movement) who portrayed this protest as something orange."

Oh, yes, why wasn't I there?
The biggest reason was a simple one, no transportation from Shiloh to Tel Aviv on a Saturday night. Unlike the demonstrations sponsored by Moetzet YESHA, which always took into account that without buses, nobody could make it, this one was geared towards those with private transportation, or in the Tel Aviv area, or those who traveled on Shabbat.
Another thing was that they didn't want it to look like a YESHA demonstration. As you can see in the quotation from Eliad Shraga, he wanted it to be clear that even Peace Now supporters want a State Commission of Inquiry. Look at the pictures here, which I didn't succeed in posting. For example, the sign, which says: "Olmert and Chalutz--Go Home," doesn't have the ב"ה in the right upper corner, which is part of the "template" for religious Jews.
I'm glad that the turn-out was good.