There are lots of intricacies with seating Scott Brown.  However, as many have pointed out, Brown can be seated with the unanimous consent of the Senate.  (This was the method used to seat Teddy Kennedy 47 years ago).

What is the downside of a Republican senator asking for unanimous consent for Brown's immediate seating?

Of couse, it only takes one Democrat Senator to object, which they might do.  But, it would be a HUGE slap in the face to the voters of Massachusetts, while serving as a careful reminder to the rest of the country that the Democrats are not about the "will of the people" but pure political might.

All we have to do is give them the opening for delivering that message.