The trade market will see increased activity this off-season since, you know, the free agent market is shallow and filled with players who will receive contracts way outside of their pay grades (well, that's nothing new).
Renck, however, does bring up the possibility of the Rockies looking into acquiring Cliff Lee of the Indians. 2007 was a lost season for Lee as he began the season on the DL with a strained abdominal muscle. Making his first start in early May, Lee would pitch for the Indians until the end of July. He routinely allowed four or more runs, bottoming out during his final four starts (6, 7, 7, 8 runs). He spent August in the minors before returning for September, and only September.
He had a good year in 2005 (18-5 record, 3.79 ERA, 4th in Cy Young voting), a decent 2006, and a 14-win 2004 season with a 5.43 ERA and a 1.503 WHIP.
Still, he's a left-handed starter, can be on the mound for 200+ IP, and is cheaply controlled for the next three seasons. On 8 August 2006, Lee signed a three-year, $14M extension with an $8M team option for 2010.