UPDATE: The idea was thrown out there in the comments section below that he may be looked at as potential depth at Strong Safety. His size is more suitable to that position and he's fast enough to play there. Pete Carroll's strong safeties generally are kind of like linebackers anyway, playing up and stuffing the run, so this could make sense.
With the Hawks' depth at LB in flux - Will Herring, Matt McCoy, and LeRoy Hill are all Free Agents - Carroll and co might be looking to add some depth in the upcoming draft. Smith is an amazing athlete - he's 6'1, 225 and recently ran a 4.47 40 yard dash. He's on the very light side for a linebacker, but weight can be added. He also registered a 39 inch vertical, a 10-5 broadjump, and benched 225 28 times - all pretty ridiculous numbers for a guy his size coming off the injuries he's had. He's coming off a knee injury, and has also had issues with his shoulder and ankle that will hurt his draft stock so he looks like just the type of player that John Schneider and Pete Carroll target in the later rounds.
If he is drafted, he'd most likely be brought in as a special teams contributor a la Matt McCoy - another 6'0, 235 lb speed linebacker.