The relevant text can be read here:

http://www.ripten.com/?p=235

The full transcript is a financial report for Take Two, so it's long and painful to read fully. However, you can see the information is clearly there by reading the full thing (if you have time):

http://seekingalpha.com/article/38017

You can also just search for the term "episodic" to find the text quickly in that page. This gives us several bits of information:

1) The added content for the 360 is almost certainly genuinely exclusive -- not "exclusive for a while," or "exclusive but the PS3 gets its own content" or "exclusive to online because the PS3 gets the content on the BR disc." It's flat out, totally exclusive to the 360, with no corrolary for the PS3.

2) Microsoft is spending big time. I have strong doubts they could possibly make money on this deal, but I suspect that isn't their goal anyway.

50 million???? LOL.... wow way too much to spend for additional content seriously...

I had heard 30 million elsewhere and thought that was insane but this is just ridiculous.

Anyway it's good for 360 owners when they get to play the extra content (it won't be free either I'm sure)

I'm not so sure. This is the most important third party franchise on any console, without question. In America and Europe, it dwarfs everything else. 

For people who want to play this game, they now can choose between buying a 600 dollar console to play GTA IV, or a 400 dollar one that has the definitive version of the game. This is a game that sells a ton of consoles, and I think it's reasonable to estimate that 75+ percent of the people that buy a console with this game in mind will be buying a 360 now. 

Also from reading that I found out the additional content is coming in two chunks one in March 08 and one later in 08 with 25 million dollars for each lol

I think it was already gonna be a much bigger seller on 360 anyway but I guess this pushes that further...

It's scary how much money MS is willing to use in this console war... Sony right now needs to step up and start buying 3rd party exclusives before things start getting worse lol 

Right, I'm not just talking about how many games it sells, because I absolutely agree the 360 had a lock on copies sold; I'm talking about systems. Keep in mind that the last iteration of Grand Theft Auto sold more copies than the last iterations of Final Fantasy, Metal Gear Solid, Tekken, Devil May Cry, and God of War combined. It will be difficult to discern how many systems this game sells, but it's fair to estimate that whatever it totals, the vast majority of those systems will be 360s, not PS3s. 

 So you're assuming the average consumer knows about the GTA IV additional content coming in half a year? The only people who will know are ppl like us following the news.

Well if Microsoft is not totally dumb, they will do a lot pub around and GTA IV will have a big sticker with enormous letters saying future addons only available on xbox 360 so everyone will know it when they'll buy the game.

Do you think that will have a massive effect on the opinion of an everage person who doesn't know about the stuff already? I certainly don't, but they should do that for sure.

I have a videogames shop and i can tell you for sure that people who will see such a sticker on the 360 version will hesitate a lot before buying the ps3 version. And of course, if they have a ps3 AND a x360 they will buy the x360 version.