I wondered that, too, jes. He'd already been released prior to his nice-looking 2010 season. So teams haven't seemed to find him as desirable as his 2010 numbers would suggest.
The Indians sent him down to AAA in 2010 on July 20th after 25 innings with an ERA of 4.18 at the time, and then was called back up at the end of July and finished with an ERA of 2.97 in 36 total innings.
He then had a poor spring training in 2011, "in which he allowed 10 runs on 13 hits in 5 2/3 innings, Lewis was outrighted to Columbus on March 22. He was released on June 24, after recording a 5.14 ERA in 28 innings while with Columbus."
Then after his release on June 24th, NO ONE signed the guy until Arizona did at the end of November in 2011.... which would make me think he may have had arm problems which either required minor surgery or which he (and Arizona) thought might be helped with rest.
His FIP was 3.41 in 2010 and his xFIP was 4.53, so his numbers imply a lot of luck in 2010. Fangraphs has his average fastball at 89.9 so unless he has some great breaking stuff he screams Casey Coleman to me.
It is not just 2010, as I mentioned before, he has had an ERA+ of 115 thru four seasons in the majors in 161 relief games at age 26.
Finally, one reason to hope Lewis does well with the Cubs:
http://soccer.altweet.com/2010/07/30-hottest-wags-in-major-league.html