Our kernel is 2.6.13.2 from kernel.org with most options enabled (as modules, where possible). If you install on a running Debian, you should still keep a keboard and a monitor around, just in case as Pluto will install the kernel too and if you have something "non-standard" in that machine and it doesn't boot, you'll need those (If it doesn't boot, let us know). I haven't attempted and install on top of a Debian system with the new scripts. Other stuff may also break or get replaced.