If I remember correctly Randy (Sirquack) is using it with his HTPC. I'm sure he'll chime in; if not pm him!

As jmone pointed out MediaPortal is great but involves a bit of tweaking to get it to do exactly what you want. Remember that it's being developed for free and I think it works pretty well for a product that hasn't acheived commercial maturity yet. It has its flaws but it's getting better all the time. I'm planning on using it whenever I build my HTPC.