Only the Jaguars would actually trade for an offensive lineman that everybody and their mother knew was going to get cut fairly soon. But, as the 2010 NFL Draft showed us, the Jaguars are not all that concerned by what people think of their personnel moves.
Per PFT, the Jaguars have traded for guard Justin Smiley. The Colts and the Seahawks were rumored to have some interest in Smiley, but like everyone else they thought it best to just wait for the Dolphins to cut him, seeing as no one in their right mind would trade for an unwanted guard with a bum shoulder. However, leave it to the Jags to screw everything up by doing what no sensible team in the league would do.
No details on the trade, but it is probably conditional on Smiley making the final 53-man roster. If it isn't, the Jaguars front office is even more incompetent than previously thought, and that's saying something.