I can't stand DRM, and have said so many times in my short time on this forum. I believe it's a parasite that the nascent eBook industry can't afford as it fails in its stated goal of copy protection and puts obstacles in the way of the honest customer. At the very least I find the presence of DRM to be a value reducer. I also dislike PDF as a reading format. It's a printing format, pure and simple.
I don't mind mobipocket, their .prc container works well with uBook which is my preferred reader, and it's easy to convert things to it. It may be proprietary but it fulfills my needs.
As to eBooks, I buy Baen or multi-format from Fictionwise. The only way to get the products we want is to vote with open wallets. If I only buy unencrypted eBooks, and turn down the secure formats even when they are free that provides people like Fictionwise with ammunition. They can go to publishers and say that people spend more money on unencrypted eBooks, and if they provide theirs in multi-format sales will go up.