Obama gets laughs from Congress ...inadvertently.

When Obama said that "details remain to be worked out", he was surprised by the laughter that came from members of Congress.
From Best of the Web by James Taranto:
As for the claim that a government insurance company is the route to "true choice and competition," Obama may or may not sincerely believe it. But he doesn't have a Nobel Prize in Economics. Paul Krugman does, and in a 2007 interview with the hard-left cable-access show "Democracy Now!," he explained the purpose of proposals for a so-called public option (quote is at 2:17 in Morgen Richmond's video):

Crucially, they also allow people to buy into a publicly run plan, which would compete and, I believe, actually would in the end kill the private plans in the competition.

So when Obama talks about "competition" tonight, he will be advancing a plan that experts see as a way of snuffing out competition in favor of a government monopoly.