I bought a backpack from them in 1999 which came with a lifetime warranty. I then lived out of said backpack (never changing bags in all that time), punishing it as only someone with 5 planets in Taurus can. Though sturdy, my adventures put it to the test and this spring one of the straps broke.
I contacted Eastpack and asked about the warranty (I had saved my receipt) and they got back to me right away and asked me to return the pack to them (sans receipt, they don't require proof of purchase to fulfill the warranty). They explained that they will always try to repair a bag first before replacing it (yay sustainability!).
They just called me because they want to replace my pack rather than repair it (when I say I used it hard, I mean HARD) and no longer carry that exact model. They questioned my preferences and are sending me a new pack which will continue to have a lifetime warranty.
It's nice to know I will never ever have to purchase a new backpack. If you're looking for a pack or bag, I highly recommend them.