In the end, I don't believe more os choices is the answer. This is the one case where more choices, imho, would actually hurt the consumer. Windows has it's issues, and some of them are great....but a world of many choices of consumer operating systems would be a nightmare for "Joe user".
Lets say EA gets a kickback from Sony, so now you must have Sony's OS to run any EA games...but UBI signs a deal with...Apple, so now you have to have OSX to play any UBI games....and on and on. Having to have the specific OS for the specific hardware/software you want to use...could lead to needing several OS's installed just to use all the software you'd want.
Windows has become more than an OS. DOS, was an OS...Windows is a collection of many applications, network infrastructure, etc. What I'd like to see is a modular approach to Windows, sortof like Linux. I'd like my core OS that I boot into to be as streamlined and basic as possible...like the mini OS's built into consoles, PDA's, etc. Sell that cheap, then if I want all the 'other features' I can buy them.
For me, I don't need speech recognition...I don't need indexed searches (I use Google Desktop...which does a much better job)...I don't need Windows to hold my hand with it's incessant popups and warnings...I don't need the ability to restore a previous configuration, I can do that better myself...I don't need many of the things I pay for in the Windows bundle.
Vista is a step in the right direction, as far as version choice....but Microsoft shoots itself in the foot because while the basic versions are cheaper...they are just as bloated as their bigger brothers without the benefits they offer. So for a person who gets Home Basic...it's just as slow and inept as Ultimate...yet without the benefit of Ultimate 'oooh ahhh' apps.