crazy_dave: I think DRM does not necessarily have to mean a loss of game preservation (though it certainly means that now I grant you). But changes on that front would have to involve digital consumer protection laws that don't yet exist. :)
StingingVelvet: DRM wouldn't harm game preservation if it was patched out eventually all the time, but companies have shown very little interest in doing so. The rare examples of it being officially removed (Alpha Protocol, Far Cry 2, etc.) pale in comparison to the overwhelming number of titles that still require it.
It's frankly painful to install a 6 year old game like Mass Effect and still have to manage my 5 SecuROM installations. Not to mention of course that patches to keep games running well on modern systems basically do not exist. GOG's business model is about paying for such a thing, after all, and can only be done when licenses and rights are all set up nicely and modern, which isn't anywhere near always the case.
Basically if companies showed more interest in preserving their games I would show less concern about DRM ruining it. On PC it isn't as big a deal because open platform means the community can take care of it, and this is why I go ahead and buy Steam games, but I would never support DRM on a closed system.
I see what you mean which is why I think it would take consumer protection laws either forcing patches or forcing authentication servers to be maintained indefinitely (that would kill DRM :P)/forcing a shared authentication protocol so that DRM doesn't tie your game to one service or server or forcing that every DRM version has a DRM-free version that could be bought somewhere else. Something along those lines, but it would almost have to be codified because I agree, I don't see companies doing any of the above voluntarily for the consumer (at least not ubiquitously).