Basically there are two key pieces. First, they allow recording to other drives on the network, not just drives in the DVR. This is a cost reduction move for the IPTV DVR providers they're targeting. They can skimp on the include storage, and sell it as a feature but having users use their own drives. However, this is risky - when you use network storage then your DVR is only as reliable as the network. If you have any network issues, it can't record. And a home network, especially WiFi, can be too slow to handle network read/writes. And if you do anything else heavy on the network you could impact the recording. I'd have the same concerns over devices like the Hava which can act as remote tuners for Windows Media Center. You have to be positive the network can handle it.
The second thing is what has been getting attention - a peer-to-peer (P2P) feature. Users with one of these DVRs can request shows from other DVRs. Some blogs are hailing this as the first P2P DVR - forgetting that ReplayTV allowed sharing between 4k and 5k units. (And that it also got them sued into bankruptcy.) But the devil is in the details - in this case, users can only share content from the IPTV network with other users. Note: A subscriber can only access and view content for which they have a valid subscription.
If you read the press release, these features are really aimed at allowing IPTV providers to offer inexpensive DVRs and services. Leave out the hard drive and allow the user to supply their own storage on the network. Instead of having to provide server and bandwidth capacity to allow users to download shows, have other users supply both by using P2P. This isn't open sharing of any content.
I picked up the new from pvrwire