When you think about the "first" attempt of a steam client it is more likely that every data is hold in your home. That means that what U will get is just an icon and a small download tool - which could be easyly be a script - i wrote my own script a few years ago to do that. Steam usually verifies/updates the client on start so i do not think they will ask for a root pw every time there is an update.
No announcement yet.
Valve's Full Linux Push Talked About For February