No large 3rd party is going to be bought out. They are large cause they can survive on their own haha. Meaning they want to stay independent.
Now I do think down the line we could see a very strong partnership between Nintendo and Sega but not Nintendo buying it out.
Now for companies Nintendo might possibly buy out, Camelot is the first one that would come to mind. The biggest company Nintendo might buy out is Hudson. But Nintendo is set to start rebuilding their Dream Team that they had during the N64 era. The buying of Monolith Studios was teh start to taht. And with NIntendo's market value, profits, and sales increasing so much its only economically wise to make yourself a bigger company buy doing this. Nintendo is set to expand and in the next few years they should buy out a few smaller companies of the size of Monolith Studios.
Sony I really don't see too many companies that they would buy out. Although I'm sure they are interested in buying Rockstar but Take 2 wouldn't give them away.
Microsoft on the other hand isn't really set to buy any companies. I mean if you haven't already noticed MS has been dropping companies, Bungie being the largest. This may be hinting at that MS isn't planning on staying in the console wars too much longer. Or possibly they are dropping to look for new talent. I don't know but the first one is probably more what's going on.
You may see soon that MS gets rid of Rare. This may be the reason why Banjo Kazooie 3 hasn't beem shown and why Viva Pinata Party animals isn't being made by Rare.
