The US has about 48,000 troops in the Persian Gulf, and another 10,000 in Afghanistan and neighboring areas. The number of troops headed to the Persian Gulf (usually unannounced) is growing.
The campaign to oust Saddam from power has already begun. It's an Information War campaign of bluff, subterfuge and threat. Making Saddam and the Iraqi people believe that the American troops really are coming is having an effect. Lower and mid level members of the government are looking to make deals, and the secret police are easing up on their normally capricious and brutal behavior. Negotiations are apparently under way to mount yet another coup against Saddam, one that will actually work. In anticipation of that, work continues among the many exiled anti-Saddam groups to work out how a new government would be formed. Tribal, religious and clan leaders inside Iraq will have to be consulted to make this work, but communications with these people is still difficult (but not impossible.)
Negotiations with the UN over the terms of arms inspections in Iraq and the use of force against Iraq continue. The feeling is that the UN resolution doesn't mean much and is just being done as part of the psychological warfare campaign against Iraq's leadership.