I've been using Win 7 at home ever since the beta was released.
It networks just fine with other machines. Only issue was setting up shared folders on it - that took a bit of Googling. Turns out there are security policies set by default that prevent other OS's seeing SMB folders. Can't remember the exact details, but its solvable.
Otherwise, I've been pretty impressed - much more so than I was with Vista.
AH2 runs on it fine btw.