Well, our CCTV system in the building is now completely IP. True it is not real-time, but it is much more flexible: instead of requiring a dedicated coax from every camera to the "recorder" box, and a power connection at each camera, it now uses an ethernet network with 801.11AT PoE and every camera is only wired to the closest switch. (and it can be done over WiFi when desired)
It is not related to internet, the camera's and the recorder are on an isolated VLAN that has no link to internet. (those devices are to insecure to connect them to internet, especially from the company network)
The picture is Full HD, a big improvement over the old PAL based system. (which of course was better than an NTSC based system)
The only point that holds is that it is not real-time. There is a delay of 1..2 seconds.