said by TKJunkMail :

This might be interesting depending on what they charge per month for the service. A DVR can run anywhere from $10 to $20 per month for each DVR from a cable company. But a hosted server could be used from multiple TVs without having a DVR on each TV.

It would also depend on whether they allow fast forwarding thru commercials or not. A service that doesn't do that would be pretty worthless for most people.

Also with a networked DVR service, you are subject to the same problems people have with VOD - and that is all the available channels available at a node for VOD can be used up by neighbors and you may get an error msg that you can't play back your recording when you want to. Of course, a good deployment of SDV could mitigate this problem.