The Seahawks did in fact part ways with former Rams DE Grant Wistrom. The team's signing of elder statesman Patrick Kerney made Wistrom somewhat expendable. Wistrom came to Seattle in 2004 with a big, superstar contract, and I think a lot of fans never saw his play and the contract value reconcile themselves. Again, it's another lesson in making a defensive signing that bills itself - whether through hype or the contract value or the combination of them both - to be an end-all solution.
Wistrom told the press that he would like to return to St. Louis; he is a native of Webb City, MO, about 4 hours SW on I-44. Depending on the offer sheet he would require, it wouldn't be a bad signing at all for the Rams. Wistrom would give them veteran leadership on defense, and fit nicely into the DE rotation. By not having the 30-year-old Wistrom as an every down DE, he should be able to hold up well through another season or two and be able to contribute at a level above the average two down DE.