The vast majority of them will be. I'd already discussed my intent to use some of it to help me get to DevCon next year, but seeing as there's no a plan to use the Rockbox Fund to help some of us 'mericans (and others, I assume) get there next time around, all of it should be going to it.
That being said, "all of it" is none right now (until a certain mark is hit, when they send out the first check). It's mostly a trial period, I may take the store down after the first check is sent out from CafePress, and see about coming up with a better way to do merchandise overall.