1000ap proc and 450haste proc both sound decent, even though i hope 130agi will be the best as i don't like procs that much. Plus, 130agi sounds better than those two in case you should shift to bear and tank something.
Still, i did no math at all so i'm just taking a guess.
"Seeping crest of turbidity, arrogant vessel of lunacy.
Boil forth and deny, grow numb and flicker, disrupting sleep.
Crawling queen of iron, eternally self-destructing doll of mud.
Unite, repulse. Fill with soil and know your own powerlessness."
Avalance seems to have a 5 PPM for about 500 nature damage (it does seem to get buffed by shammy mastery).
so that like 2.5K extra damage every minunte ? seems totaly useless imo :P
now lets assume the +450 haste and + 1000 AP are on same proc rate / uptime then it get easy to decide witch one is best :P
using our current kitty stat values:
450 haste * 1.96 = 822
1000 AP * 1.41 = 1410
130 agi * 4.70 = 611
so it realy comes down to the uptimes
so it says on wowhead cumment that it last for 12 seconds and has a 45 seconds internal cooldown = 57, lets round that up to 60 seconds :P so then it has a 20% uptime
1410 * 0.20 = 282...
so it seems the +130 agility enchant wins big time but since the difference is so big my math is probely completely wrong :P also the stat values points will chance a lot
---------- Post added 2010-11-27 at 09:38 AM ----------
done ome more though about this
if 1 agi gives us more then 3 AP we will get like 400 Ap for the 130 agi
this means that the +1000AP enchant needs to have more then a 40% uptime to becomes better witch its probely verry unlikely :P