I’ve backported keepalived from Debian Lenny to Etch (4.0). Both i386 and amd64 are available for download here. There was no need for changes from the original package, only a recompile.

I’m thinking about packaging feedbackd and use it together with keepalived to adjust the weight of realservers during runtime. I’m not sure if it’s feasible, else I will write my own poor mans implementation.