It would not be any time soon for the following reason:
*All their current IP belongs to Sony
*All their project are funded by Sony, they enjoy an intimated relationship with many other studios from Sony, especially Naughty Dog.
*To go multiplat means that it would be unlikely for Sony to fund their next project, this means securing a third party publisher as Microsoft will certainly not fund a multiplat, (if it becomes a 360 exclusive then whats the point of making the switch?).
*In the current financial climate, Insomniac must seem like a dream job within the industry, they have a fairly low turnoever rate, is constantly rated as one of the top small bussiness in the coast, it is financially secured and all project in the forseeable future have funding.
Despite all this they are still independent. At a time where other companies are losing money, firing staff or closing down entirely, insomniac is actually expanding and opening an second office.
And btw, Insomniac is one of Sony's biggest money cow, their projects are cost effective, fast and always a commercial success, they might not have a 'massive' drawcard like Bungie or Rockstar, but they are still VERY successful.
