There is no such thing as a "final" roster in the NFL and especially in Seattle, where the Seahawks have shown they'll churn the roster with abandon.
The Seahawks, though excited about their young wideouts, could use veteran insurance at receiver after determining Mike Williams had "topped out" in Seattle, in the words of coach Pete Carroll. They also could use insurance for starter Sidney Rice, who is coming off two shoulder surgeries and carries a concussion history into the 2012 season.
Edwards, 29, is two years younger than recently signed receiver Antonio Bryant, who has been battling a hamstring injury early in camp. The team has not announced Edwards' expected signing or a corresponding roster subtraction. I see no harm in giving Edwards a look. He averaged better than 17 yards per reception for the New York Jets in 2010 before injuries limited him in San Francisco last season.
Update: How the Seahawks created a roster spot for Edwards, who is wearing No. 17.