I know beserker is better, but thats not the right math at all, man. if it procs 35% of the time, the number of attacks per minute that can proc the enchant and the length of time it stays up for are needed to calculate effective AP.
on wowhead there is some discussion
http://www.wowhead.com/?spell=59621#comments
It works out that for a typical ret pally, the UPTIME is 35%, not the proc rate, so yes, you should see an average around 120-160 ap gain depending on gear and rotation.
The ppm is about 1.2, but that effectively increases with haste and a lot with other non-autoswing abilities going off.
Also, we discussed this whole thing like fifteen threads down:
http://wow.allakhazam.com/db/class.html?wclass=2;mid=1235163951123401106;num=3;page=1