WASHINGTON -- Barack Obama spent most of the past two years bashing George W. Bush, but that's all over now.

"Here in America we can compete vigorously in elections and challenge each other, yet come together when things are done," Obama's transition co-chairman, John Podesta, said at Tuesday's first formal briefing about the shift in power. "They've been quite cooperative, and we've tried to be cooperative in return."

So what about reports that the Bush White House staff is already angry at Obama's not-yet-in-the-White-House staff over leaks from Monday's meeting between the 43rd and 44th presidents? Podesta claimed it was all a misunderstanding. Yes, Bush told Obama he'd like to see a Colombia free-trade agreement pass Congress this year, as several news organizations reported this morning (apparently irritating Bush's team). But no, he didn't say that the current administration would only back a new stimulus package if Obama signed on to push for the Colombia deal. "Whatever happened this morning as a result of reports -- which I think were not accurate -- we cleared up," Podesta said.

The only real news out of the briefing was that Obama will ban lobbyists from working on the issues they lobbied on with the transition team. That means lots of Democratic lobbyists who hit K Street over the past eight years because Republicans controlled the government won't be involved in planning for next year, but it also means Obama is keeping his campaign promise not to let lobbyists run amok in the White House. "These are the strictest ethics rules ever applied," Podesta said.

There probably won't be any Cabinet secretaries named immediately, Podesta said. Though Obama is trying to work fast, no recent president has chosen department heads before December. By early next week, teams from the transition group will start arriving at agencies and departments to conduct a review. Another team is already reviewing Bush's executive orders, to see what Obama wants to overturn immediately and what he wants to keep.

Other than that, Podesta didn't have much for the media. But the briefing still drew a big crowd. Reporters lined up an hour early to get through security at the transition headquarters, about 10 blocks from the White House. Staff had to squeeze past the line to come and go from the building. At one point, Obama's Senate chief of staff (and another transition co-director), Pete Rouse, managed to walk out, hold a meeting on the sidewalk, and get back in without any of the hordes of press apparently realizing who he was; he hardly ever speaks to reporters. (When I said, "Hi, Pete" and tried to stop him, he ignored me.)

Obama, meanwhile, is still in Chicago, and aides said he may spend most of his time there for the next few weeks. His White House chief of staff, Rahm Emanuel, is shuttling back and forth between Chicago and Washington, meeting with Obama and Podesta and other aides regularly.

For the time being, it sounds like the transition team is mostly trying to stay out of Bush's way -- while getting ready to make wholesale changes as soon as possible. "We recognize that we have only one president at a time and that President Bush is the leader of our government," Podesta said. "But President-elect Obama wants to ensure that we hit the ground running on Jan. 20, because we have no time to lose."