Funny enough, Apple has owned a stake in the company for some time, and at one point there were rumors of Apple taking over the company, but those either fell through or didn't go anywhere. According to this
trading site, Apple owns slightly more than 8% of Imagination's stock. Perhaps some of the price collapse is due to Apple selling off their shares as I imagine they would want to divest themselves at some point. Intel also previously owned a large chunk of the company, but I think they sold off all of their remaining shares a few years back. They seem like a more likely candidate for buying up the company on the cheap since they're going to see more competition from AMD in the APU market and need to shore up their graphics performance.
I can't imagine Apple being allowed to buy the company after this announcement as regulators would throw the book at them.