I'm not sure what to make of this, but according to Schefter, the Steelers made an effort to get Jake Long.

Adam Schefter ‏@AdamSchefter
Just before OT Jake Long agreed to a four-year deal worth up to $36 million with Rams, Steelers made a play to try to get him to Pittsburgh.
Most of the remaining guys on the tackle market appear to be RTs, so I'm not sure if the Steelers would make a play for one of these guys (with Adams/Gilbert to compete at LT) or if their interest was just in an elite LT like Long. Here is the list:

http://walterfootball.com/freeagents2013OT.php

If Schefter's report is true, then perhaps the Steelers reported interest in Dumervil is legit.