also keep in mind that if you're really insane about the weight, you can get carbon fibre poles that weigh next to nothing. But really, with the standard aluminum poles it doesn't weigh all that much anyway. And since the tent should be carried on the bottom side of your pack between the pack and the sleeping bag, all the weight will be on your hips anyway so you won't notice it
A 3-4 day backpacking trip, my wife and I each carry about 40 lbs, but we carry crap we don't need too. We could go lighter by bringing MRE's since we wouldn't have to carry cookware then, but who wants to eat that crap for 4 days?