ok no offense but i think that pack will be to big for a two month trip im going on a two month trip myself leaving on sept 5th and im bringing a much smaller back pack, im taking the northface terra 40 pack. your pack is about 87 litres and i think that the pack that would be suited for a trip similare to the ones we are going to partake in would be a bit smaller something between a 40 litre bag and a 60 litre bag just remember to take less then you think you’ll need and think about other laundry options, less clothing and more time spent doing laundry. it will lighten your pack alot and just remember to read the threads throughout this site.
 
an idea of how big a 40 litre bag is : 5 shirts, 4 shorts, 2 pants, 2 light jackets, a sleeping bag, a hammock, extra ropes, a bag full of toiletries, digi cam, 1 pair of sandals, 1 sweater, 7 boxers and 7 socks, and a mess kit( pot, pan, cup, plate, fork,knife and spoon)
 
and thats just in the body of my bag theres more room i just havent figured out what to put in them yet.   good luck

It’s a good pack if it is comfortible and fits properly with the load which you want to carry. 9 weeks is a fair amount of time that size pack should do you fine, besides you can always lighten the load and remove items if you find it too heavy. If you buy to small a pack where are you going to put all the crap you buy on the trip.

As Kiwirob said, fit is really important, and I agree with Ryan that it’s bigger than you’ll need.  I travelled with a pack that big once because I had to carry all kinds of equipment, books and extra clothes for a research project.  I never would have needed that much space for a regular trip, but it won’t kill you to carry a pack that big as long as it fits right and you don’t stuff it to the gills. 

If you don’t mind returning the pack you bought, you can get somethign a little smaller and with some nice features for travel for less money.  There’s a travel pack from REI that has a 55 liter main pack, a 20 liter detachable daypack, features panel loading, and a security cable sewn into the pack for locking it to something.  It’s on sale for $130 right now: http://www.rei.com/product/747912