White92 asked a very good question in the comments:
Maybe Turner is not the next Priest Holmes, but Turner is the running back most likely to step out of another back's shadow and become great like Holmes was once he got to Kansas City. Turner was better per play than Tomlinson last season according to Football Outsiders DVOA. I know it was just one season and a small sample size, but Turner has been really good for the last three seasons averaging an awesome 6 yards/carry for his NFL career!
Teams should never trade their 1st or 2nd round pick, but an exception would be made for Turner. Unfortunately there is no way that San Diego would accept only the Packers 2nd round pick. They have a restricted free agent tender on him that would make any team that signs Turner forfeit their 1st and 3rd round picks, so that is San Diego's bottom line offer. Plus Houston just gave up two 2nd round picks and swapped 1st round picks for restricted free agent QB Matt Schaub so San Diego might ask for the same package too. When San Diego traded away the rights to Eli Manning, GM A.J. Smith received two first round picks which became Philip Rivers and Shawne Merriman. Trades with San Diego don't come cheap. Turner is so good that he still might be worth it, but because the price is so high, the risk is too high and they would have to pass on it.