Well, Rhonin did mention some things which are correct, and of which I fail to believe your assertions. There are 19 members of the BR association who collect royalties. I fail to believe that 18 of them would sit back and let Sony take 25% of the total. I could see possibly 10% or so, but I can't prove one way or the other.

As for the companies, yes, Nintendo has always had its own format. There is a possibility that they could still stick with a DVD-base, as it would be the easiest and cheapest to press. Or, depending on how the market plays out with the cost of flash media, I could even possibly see them going back to cartridges. If, by the end of the Wii2's life, a 64GB cart could be made relatively cheaply, it would give them even more space for games than a dual-layer BR. And since the 64GB USB drive already exists, by 2015 (mid-way through a Wii2's lifespan), I could see it being feasible. (Or they could make the cart a bit bigger and use multiple cheaper chips, just like the old days.) So Nintendo's not locked into BR.

And Microsoft? There's only one way I could see them going with BR for the 720, and that's if they keep the multimedia angle. But by that point, will people still want to buy one for a BR player, especially given that some of the standalone players have already come down below the 360 Arcade? They would not be able to hedge sales on systems too well for this, like some of the PS3 sales have done. But, given that both the Xbox and 360 used a DVD format, I do think Microsoft will want to move on. Recall, however, that they were part of the HDDVD group. While the format may be dead, the technology still exists, and it would be cheaper for Microsoft to use this than BR, which leans me more toward them actually using a (maybe) modified HDDVD disk rather than a BR.

So no, Sony's not guaranteed a load of money. As Alterego-X mentions, there are a lot of assumptions, both in your post and mine. I can't rule out that both Nintendo and Microsoft will use BR entirely, but I just can't see it happening.