The NFLPA has released a public spreadsheet, which will be updated several times a day, containing their information on each team's salary cap situation. Bookmark that, please.
The Seahawks, as it would appear, still have $9,105,008.00 in cap space for the 2013 season after rolling over $13,265,802.00 in 2012. That $9.1M is 12th in the NFL. Jacksonville, Cleveland, Tampa Bay, Cincinnati, Philly, Green Bay and Buffalo lead the pack. Of note: Arizona and St. Louis are currently the two teams in worst shape against the cap; STL with just over $500k in space to work, and Arizona currently in the red. San Francisco fares a little better, with just over $3M left to spend.
If you hadn't heard about this upcoming year's cap situation, the NFL's landed on an unadjusted cap at $123M. Seattle had $13.2M in rollover from last year (that's how far under their adjusted cap they finished last season) - that puts Seattle's spending cap in 2013 at about $136.2M.
Of course, none of these numbers are super surprising, thanks nearly entirely to Davis Hsu's obsessive tracking of Seahawks' player salary data. Hsu has been regularly updating his numbers over the past year or two so this now-public record will be a great reference point. Check Davis' most recent post on the Salary Cap below, and keep in mind, as more extensions come for Seattle's core group, cap casualties will come with them.
Seahawks offensive salary cap through 2015: Stop worrying about keeping the band together - Field Gulls
I see fans worrying about 2015 because of the recent amazing acquisitions of Percy Harvin, Cliff Avril and Michael Bennett. Stop worrying.