Over-the-air HD video stored as a Transport Stream is up to 8.3GB/hour. It's an MPEG2/.AC3 stream which is encoded at typically just over 19 megabits/sec. DV format video is 25 Mbits/sec (but with overhead is closer to 30.)
Not quite... If you record DV format, a MiniDV tape will give you 60 minutes. The same is true of HDV, 60 minutes. If you record DVCAM format then the 60 minute tape will only hold 40 minutes, but this is because DVCAM mode records at a faster tape speed, not because of a higher bitrate. The video bitrate of DV, DVCAM and HDV are virtually the same.