Broken Steel DLC priced, dated

Irrelevant. A stupendous majority of people who use Windows as their operating system don't play games like Fallout 3 on it. If you can find me proof that 0.1% of all Windows users worldwide have loaded up and played Fallout 3 on Windows, I will truly be amazed.

Look at the history of Bethesda's engine here. It was designed to run on an Xbox 360 and a PC back in the Oblivion days. The similarity of the APIs you use make that a very viable prospect for any developer. The PS3 was an afterthought as is evidenced by the fact that Oblivion came out much later. They managed a simultaneous release of Fallout 3, but given the obvious maturity of the engine on other platforms DLC could very well have technical issues with their code on the PS3 that they have not yet overcome.

Now, given that there has been no confirmation nor denial of any MS money deals for the DLC here, is this alternate theory really that hard to believe?

It makes very little money from the PC gaming side of things. Those 800 MS Points that you guys hold so dearly will cover real costs like data hosting and publishing. On a PC, as there's already a clearly identifiable trend that the majority of users won't use their PC for games like Fallout 3 there's virtually no incentive for a company whose main product is a dominant operating system. The Xbox however is, of course, a different story.

I'd also like to see you back up your claims that playing it on a PC means you aren't playing it on a PS3. I regularly play Left 4 Dead on Xbox and PC for example.

*ahem* Like I said, there's nothing I find funnier than people who know nothing about the games industry making wild claims.