It's an excellent read, so click the link and read it all, but let's pull out the most significant lines:
Norris threw 176 innings last year, the most he's ever thrown and more than double his '08 innings. I think the Astros need to monitor his workload carefully this year, especially when he gets past the 100 inning mark. Assuming he avoids further elbow problems, I think Norris will be a league-average pitcher in 2010, then take a larger step forward in 2011.