UPDATE: The NFL Players' Association is disputing that franchise tags are available, based on the fact that the CBA that defines a franchise tag does not cover the 2011 season.
NFL teams have been informed by the league that the franchise tag will be available for use this year.
While this was not a surprise to NFL front office, the Seahawks have a number of prominent free agents to consider tagging. It's difficult to see any of these candidates as worth the money, but at this point, league-wide contract standards are so inflated that the only way to avoid overpaying for someone is to franchise K Olindo Mare (the most likely choice) or not use the tag at all.
Notable Seattle free agents include Mare, QB Matt Hasselbeck (whose would have a prohibitively insane franchise contract), DT Brandon Mebane, RB Leon Washington, and C Chris Spencer.