Steam ought to, imho, forget about the idea of official support altogether. Make the system available (they can test on Ubuntu only if they wish) and then engage the community to fill in the blanks (including: you break it, you keep both pieces).
I realize that this is another step into the "open source" methodology thinking, but one can hope.
That said, it would be really nice if the F/OSS media would recognize the efforts of said communities which are doing the work regardless of Steam's official support or not. What an amazing success story that is, and some light in their direction would not only reward effort duly but it would help ameliorate some of the unnecessary cross-distro tension that comes in no small part from too much shade being cast by too few players.+Emlyn O'Regan
Agreed; I expect that Steam will grow into that with time, however .. it's the beginning of their learning curve, though with appropriate feedback they'll likely come 'round. They are a very sharp company with very smart people producing some nice product, so it is most definitely within their reach .. one step at a time :)