[Dave S]

Do you have any idea how long the ISS can last in a decaying orbit without getting a boost from a Shuttle?

The ISS does its own burns. The shuttle and the Soyuz flights only bring it supplies, personnel, and construction assemblies. They dont move it. Three astronauts are there now. They deal with the ISS. I would be more concerned with resupplying them than worrying about the damn thing coming down.

[Crusader21stCentury]

The ISS has supplies to last until June, per NASA press conference.

[CyberAnt]

The report is that they have enough supplies to get them thru June. And ... with a Russian space capsule attached, they can leave anytime they have to.