As of this post, the Senate has begun voting on the stimulus. Probably best not to hold your breath waiting on the results, though -- the vote probably won't be over until about 10 p.m. ET.
Supporters of the package need to get at least 60 votes in order to pass the bill. That's not due to a Republican filibuster threat, but because the legislation is subject to a budgetary point of order as a result of the deficit spending in it. 60 votes are needed to waive that point of order.
That requirement put the Senate in a difficult situation: With Sen. Ted Kennedy (D-Mass.) not voting, and Sen. Sherrod Brown (D-Ohio) not arriving in Washington until later tonight due to his mother's death, everyone would have to wait around for Brown, at which time the point of order could be waived and the actual vote could be held. So the two parties agreed to essentially roll the procedural vote and the official vote into one, and hold it open for the senator from Ohio. That way, once the others have voted, they can leave for the holiday weekend.
Brown won't be leaving Ohio until at least 8 p.m. ET, after his mother's wake is over, Politico's Glenn Thrush reports. The White House has arranged for a government plane to bring him back for the vote.