If DLC have to exist I think exclusives are ok as long as it is time limited, but only up to 2 months after that everybody regardless of platform should have access to them. Two things I hate about gaming in recent years are DLC and achievements that have an in game effect. Achievements that just record what you have done are fine. It getting to the point where it is possibly worth just waiting a year and buying the GOTY version with all DLC included - for the same price as the original stand alone game.

If Bethesda refuses to side with one or the other then that will put an end to console exclusive DLC

@Tru021
Sadly the PS3 version of Elder Scrolls IV Oblivion Game of the Year Edition only contained Knights of the Nine and Shivering Isles
as did the 360 and PC versions but the PC version DLC is availible on Bethesda's website and the 360 versions DLC through Xboxlive