I don't think it's a patent issue so much as a question of resources. Sure, Google, Apple, Microsoft and others have the resources to develop a similar machine, but a new type of computer would wipe out their business model in a much more devastating manner than HP. HP has the resources, but also isn't enjoying too much success to scare away this risk.
If HP invents an insanely superior computer it will still need software, and HP hasn't lit the world on fire with its software. The real victim would be Intel/ARM.
It's not like Linux / Mac OS X / Windows won't run on a computer with a huge amount of RAM and no "hard disk". Most users won't care if a 100x faster computer runs their existing stuff only 10x faster.
Or, on the other hand, Google/Apple/MSFT are actually incentivized to research this technology, precisely because it could disrupt their revenue. When new technology 5-10 years down the road threatens your present business model, it makes sense to research it so that you're prepared to adapt when it arrives.
