None. Most of those developers prefer to be a second party developers like Bungie. Having a secure platiform and publisher but the option to bail out of the deal if the publisher become "differcult" to work with is how most developers prefer how to operate. Just like the reason why Microsoft sold Bungie back to the owners, the developers core people would just leave the company and start another one. Its not the name but the people behind the name that counts.
Now if one of those developers run into financial trouble due to poor performance of their products, and then we can talk. If they have to face cutting their major work force/ shutting down or being bought out by a company then I see Sony buying someone. But until then...
I'm just saying...
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