I just got a HP Mediasmart Windows Home Server and was digging through some forums about another issue. I came across these very handy, detailed, instructions on homeserverhacks.com for how to get the remote access features working with my Apple brand router.
I'm in the middle of backing up all my systems (two Windows laptops, an older desktop, and a Mac Mini) to the server at the moment so I haven't messed with it. So far, the system has performed well. A few warnings, though:
1) The Media Collector that comes with the HP-branded models works great for automatically collecting and organizing music from iTunes. Some sites claim it does the same thing for videos from iTunes and photos from iPhoto. That hasn't been the case in my first 24 hours of experience. iPhoto's approach of storing everything together along with a DB only it can manage doesn't lend itself to sync with any other system and HP's software is no exception. Since we switched to using Picasa a while ago, which uses the approach of leaving image files where they are and detecting new ones as they arrive, our more recent photos have synced over but the old ones from iPhoto have not. I'm not sure what to think about the iTunes movies. Its amazing what the Mediasmart Server does, but it doesn't quite meet the expectations I had, so far.
2) The point of the Media Collector is gathering all your media together from different systems. You get out of this process, however, what you put into it in terms of organizing your media before the collector goes to work. Again, in contrast to its nice handling of music, photos and movies are collected into the server shares by username. Unless you happen to use the same account on all your systems with similar folder structures and everything it its default location (e.g. all your pictures you want collected in the windows "My Pictures" folder), Collector makes an equivalent mess out of your files in its shares. One option I found out about too late is enabling the Guest account on the server. This option should allow everything to be Collected under that single username.