The only solution is an independent label dedicated to surround mixes, just like what Mobile Fidelity, Audio Fidelity (etc) do for audiophiles.
How about Music Valet? At the rate he's going, we might get one release per year. :yikes
Well the truth is, we already have two independent labels that while they are not strictly dedicated to producing 5.1 mixes have done a great job of getting the majority of the recent mixes out on the marketplace for all of us to enjoy.
These labels are Kscope (with Steven Wilson, Nosound, Blackfield, Katatonia, Anathema, etc) and DGM/Panegyric (with King Crimson, XTC, Yes, The Vicar, etc), not to mention of course all of the other Steven Wilson mixes completed for other labels like Sony (with ELP), Chrysalis (with Jethro Tull), and CherryTree (with Hawkwind).
As good as Richard's intentions may be with Music Valet (and as much as everyone else on here, including myself, support him), chances are unless he is able to get a 5.1 mix of an earth-shatteringly significant album made, he's not gonna make enough sales to survive in the marketplace by ONLY selling 5.1 mixes.
Stereo is still the norm and we all still listen to stereo when we can't get access to 5.1, like on computers, iPods, and cars, so only providing a 5.1 mix is probably not a financial safezone, especially giving how much music sales have dropped off since the millennium.
The CD/DVD-A and CD/Blu-Ray releases that have been or will be released are our best chances to help give 5.1 surround a proper bounce back.