More important is a battle of open vs closed, DRM and control encumbered vs free. Both MS and Apple are on the dark side of this, so watching the Apple win isn't something that society will benefit from.
Those who promote open standards, free software and don't disseminate DRM. Probably you can add to the list those who are against software patents too. Unsurprisingly Apple gets a minus on every of those points.
If I guess correctly, the question above was intending to ask which companies fall under that category. So there are a bunch who promote all or some of those values (my favorite being Mozilla for example). In general open source related companies promote open standards and stand up against software patents and DRM.
(On a side note, Apple didn't say anything on the latest development around SOPA/PIPA, simply because Apple is strongly pro DRM and they would probably support these kind of laws willingly).
Apple and DRM is interesting. They're pretty expressly against it across rich media content. Their video services are crippled with such awful restrictions due to studio pressure. iOS appears DRM heavy to discourage the unrestricted sideloading of apps, which comes with its own set of pitfalls and dangers for the end user (which, as a commenter points out above, fits within their user-focused view of systems).
Not that their methods are correct; moreso I think that they've created an interesting ecosystem where DRM is non-invasive to the point of being invisible. Really, it's always reminded me strongly of Steam.
I would argue that iTunes' strong success (with DRM forced by the music labels) helped Amazon negotiate the deal to sell DRM-free music, which in turn allowed Apple to drop them too (all music on iTunes is DRM-free since 2009).
Movies and TV shows still have DRMs, sure, but nobody, as far as I know, is distributing DRM-free video content, not Apple, not Amazon, not Netflix and not Google. That means that either all of these companies are “strongly pro DRM” or the content owners are.
DRM doesn't only apply to the media content, but to software and operating systems as well. While SOPA is mostly associated with media, DRM in essence is a broader issue.
