Cracking idea, but one big flaw well two ok three na loads.
1. Latency....as someone has suggested work packages go off and don't come back, great for file sharing, awful for rendering, encoding etc. The more real-time it gets the more the latency will delay it all.
2. Priority....if we go by the low priorty stuff being simple stuff like data packets and high priority being audio video e.t.c, then the likelyhood is your packet data packets will be nak'ed added 1. Slowly does it.
3. The most important intensive tasks that a computer processes often need nanoseconds per clock cycle, e.g Graphics has its own dedicated processor e.t.c, to harness that kind of power would be a little beyond calling the kernel.
4. As another poster has gestured, this kind of work requires local processing, multicore and farmed on a 1gbit+ lan. For high definition medical ography, e.g Radiology, MRI,CT,XRay e.t.c which does use this kind of approach, the minimum spec is 1gbit between stations using dicom.
Cheers
Shaz