The good news is that Chauncey Billups's left knee injury is just a "strain". Nothing tore or broke or imploded. The bad news is that things aren't looking up for Game Two in Boston. From Marc Berman:

Although the Knicks listed Chauncey Billups as questionable for Tuesday’s Game 2 coach Mike D’Antoni said "the probability" is he won’t be ready until Friday.

D’Antoni said that Toney Douglas would likely start at point guard on Tuesday night when the Knicks try and even the series against the Celtics in Boston. Billups strained his left knee in the final minute of the Celtics’ 87-85 Game 1 win.

Losing your starting point guard for one game out of seven is pretty massive, but I'm ever hopeful. Toney Douglas has been pretty effective (52% from the field, 47% from downtown, 6 assists, 2 turnovers) in a starting role this season, though perhaps not against defenses as heavy as Boston's. He looked pretty shaky at the beginning of Game One, shanking a few early jumpers, but looked pretty damn playoff-ready when he drilled what could have (SHOULD HAVE! AHHHH!!!!11111 [sobs]) been the game-winning three. If Douglas does start, look for the Knicks to force the tempo a bit more than yesterday, and also look for even more pick-and-roll action with Toney and Ronny Turiaf, who've quietly developed a pretty nice two-man game this year.