Accounts gets a new feature as well although it's actually not a new one. Snow Leopard sees Directory Access moved from being an app in Utilities to being a setting in Accounts. If you've not joined a domain then the button will show up as "Join" but if you have then you will see a green light (hopefully) alongside the domain and the button will read "Edit". Joining the domain is just as easy as entering the domain and then entering your username and password. The big problem is that I have yet to work out to what level of access this gives you. You've always had network drive access and this doesn't create drive mappings and Windows is telling me that my password is about to expire but Mac OS X doesn't so I don't know. I'll look deeper into it.