I think Kuo is getting written off way too quickly by ye olde conventional wisdom, as I think he's exactly the sort of guy who delivers on his early promise (like Bedard), but a few years later than expected (like Bedard).
Last year, b/w the NL and the PCL (not a huge difference, eh?), he threw just 50 innings, with a 55/22 k/bb rate, and five homers. The year before, b/w the same two stops, he threw 112 innings with an 134/55 k/bb rate, and and gave up 8 homers.
He had a 7.42 era in his 30 mlb innings last year, but his fielding-independent ERA was 4.26.
The big thing with this guy is clearly his health, but a couple of scratches at the numbers reveals a guy who could burst 'out of nowhere' to become a dominant lefty starter in his age 27-28 seasons.