That makes sense, Michael.
I overlooked the following piece of information in yesterday's IRC log: RAOF (Canonical employee)
00:52 <soreau> RAOF: So I'm steam and I want to port my client to wayland. '.. or was it Mir.. or was it, wait lemme check phoronix..'. Now what API do I choose for the official proprietary steam client that doesn't use X?
00:53 <RAOF> Well, if you're Valve, you probably use X for another couple of years.
00:53 <RAOF> Then you see what's out there.