Gammons later says five to six weeks, but that seems pretty optimistic.
It's hard to understate just how huge the drop-off from Utley to Valdez/Castro will be, but suffice to say, if the Phillies still have playoff aspirations in 2010, some big personnel moves are in order. Or some of the guys on the current roster are going to have to enter Beast Mode.
UPDATE: Todd Zolecki Tweets that Utley already had surgery, recovery timetable 4-6 weeks.
More on this as it develops...