Yey! libtorrent 0.12.2-1 is now uploaded to experimental (thanks bureado for the sponsoring! :D), soon I'll get rtorrent 0.8.2-1 uploaded as well.
I've been using it since a while and has been working great!
In a few hours the buildd network should get them built for all arches, BTW, in this version is included the support for ARM-based machines :) Prepare your NSLU2!