Sony, Panasonic and some other companies recently introduced the AVCHD format, which records high definition H.264-encoded video to tapeless media, such as DVD-Rs, flash cards, HDDs, etc.
AVCHD is going to replace HDV and be the HD video recording standard for the mass market. The new codec potentially allows the video to be about 40% less in size while maintaining about the same perceived quality as HDV (which records MPEG-2 compressed HD video to standard miniDV cassettes).
A German site published a review of Sony's first-generation AVCHD cameras in comparison of an equal-grade HDV camcorder, and the results are quite optimistic for the new format. The author doesn't make any conclusions (as far as I understood from the automatic translation, which is not so good), but I've compared several screenshots and I can't say that one format is worse that the other. This is actually a rather promising result as for the first generation of the technology (remember, it's just a start).
I noticed an interesting situation on forums of prosumer (and lower-end professional) video camera users where they mostly discuss which camcorder is better and why. Once they learned about the new format, they (mostly) started to criticize it, saying that they will stick with the old good HDV, which is more "serious", is better "because of lesser compression", and so on. It is funny to see because several years ago they were saying the same about HDV. They hated it because of the MPEG-2 compression, etc, etc, etc, and now they (probably even the same people) are fans of HDV, fighting against a newer standard. This is a fundamentally wrong position. I don't say that all new things are better then old, but most are. And the HDV-AVCHD situation is a perfect example - the future inevitably will come, and these people will enjoy the new recording format.