Obviously my posting has fallen off somewhat over the last while. Hopefully at some point I'll be less busy, and can write some more about dynamical fermions in lattice QCD. Until then, you can read
this short note I wrote about the effect of
heavy dynamical quarks on lattice QCD simulations. It turns out that unlike light quarks, it's easy to include heavy dynamical quarks. This was well known before, but nobody had sat down and compute the effects exactly.