I think this guy is a couple years away from the Cy Young. He's still 23, he's had some shoulder problems and only has one great year behind him. Yes' he'll continue to perform, and btw his split stats are great. He was actually better after the all star break, the only troubling spot is his away ERA is nearly a 4.
I don't think he'll have quite a good a year as last year, as his home ERA will most likely rise from 2.21.
I think a mid 3's ERA projection is more realistic for the 23 year old, albeit that's still a great number. His team will prevent him from getting Wins, but even if he only pitches 150 innings this year he'll still net 200 K's with only about 50 walks. Good numbers, just not a Cy young yet.
...Boston papers now and then suffer a sharp flurry of arithmetic on this score; indeed, for Williams to have distributed all his hits so they did nobody else any good would constitute a feat of placement unparalleled in the annals of selfishness. -Updike