Microsoft's Windows Home Server supports their excellent remote access software and provides an integrated backup and media server solution. Note it runs on a variant of the rock solid Windows 2003 Server OS, not Vista. So it's the only variant of XP Microsoft actively sells, though they aren't marketing WHS very hard - yet.
In the meantime Apple's Time Machine can't backup up to a (slow) USB drive hanging off an Airport.
I don't like it when Microsoft makes things I want. Windows Live Writer and Windows Home Server are annoying me.