Well now that we know the date and Dragonborn is on Steam scheduled for 5th of February 2013 I can't help my self to wonder did Microsoft pay 60 days Xbox exclusive for Dragonborn? Not 30 as for Dawnguard and Heartfire.

We will never know.

I doubt it for the simple reason that it was confirmed that Dragonborn was being released on the PC and PS3 before Dragonborn even hit the 360. The past DLC was never confirmed to be released on any platform other than 360 during the exclusivity period.

My guess is Microsoft werent overly fond of paying money to find out the PS3 DLC would of been delayed anyway so my guess is the terms of the contract was changed to 2 months for Dragonborn on PC and perhaps a possible month (or two-depending how much more work needs to be done for the PS3) delay for the next DLC on PC or PS3

There no way to know for certain, but it's a strong possibility. You don't just choose the Xbox as the "lead" platform for a DLC for no apparent reason, especially when there's a two month difference between it and the other platforms.

I dont think so. I DO think that Bethesda gets a bonus for delaying the other Ports though.
That would make sense why they delayed the PC version for so long. They delay the PC version that way when the next dlcs comes out, they can release it cor xbox first yet again for 30+ days and simply say its not Microsoft but since it was delayed last time, it taking longer to catch up and etc etc.
Dlcs keep coming out for xbox first, Bethesda keeps receiving bonuses from Microsoft, and the PC and ps3 community get to be told the reason why urs didnt come out when xbox came out was because we was catching up etc etc. Bethesda gets bonuses and at same time can throw up an excuse they orchestrated to receive extra money while making it look like their not receiving extra money.