Not sure if this is really new news, but it gives us a timetable to work with.
Wallace weighing offer - Boston.com
Rasheed Wallace is not expected to make a decision on the Celtics' offer of a mid-level exception contract for at least a week.
Update: Interesting to learn of the Cavs lack of interest. Also, it seems like the Celtics might be willing to go to 3 years (not confirmed):
'Sheed receptive to Celts, but will shop - CBSSports.com
Contract parameters were discussed -- it is believed Wallace would get the mid-level for 2-3 years -- but Wallace wants to hear other offers. According to the Cleveland Plain Dealer, the Cavaliers have yet to contact Wallace, indicating their lack of interest. San Antonio has expressed interest, and the Orlando Sentinel reported Friday that the Magic have contacted Wallace's agent, Bill Strickland.