SB Nation's Joel Thorman put together an article recently that explores Peyton Manning's options under the assumption that he and the Colts are going to part ways. Thorman compiled a list of teams that should pursue Manning, a list of teams that make sense but likely won't pursue him, and a list of teams that should not attempt to sign the future hall-of-famer.
From that article, here are Joel's lists:
As you can see from that list, the Seahawks are where a lot of people these days are placing them, firmly in the "should pursue Peyton Manning" camp. Per Thorman, the Seattle Seahawks make "a lot of sense, too. They don't have a quarterback of the future so they should absolutely be exploring Manning. I'd put them in my top 10 of teams likely to pursue Manning."
I don't know how likely it is to happen, but I can't say I disagree with the thought that the Hawks would be in the top-10 for interested teams. Whether they are indeed interested or not, they're holding that card close to the chest and there have been no leaks or rumors regarding their stance as of yet.