The Seahawks are being smart, I thought they originally made a mistake getting their fans hopes up that Harvin would be back toward the end of the season.
There is a chance, but there is also a solid chance his season is over, so it is wise to not set a definite time for his return.
. @Seahawks WR Percy Harvin underwent hip surgery today, no timetable for his return
— NFL on ESPN (@ESPNNFL) August 1, 2013