Most significant out of these new features is the Carl Zeiss (used in all Sony digital cameras) 15x optical zoom which is a substantial improvement over the previous high-end standard of 10x optical. To deal with the associated blur that comes with such an extreme zoom, Sony uses their Super Steady Shot technology which they claim achieves image stability without having to crop the picture like other anti-blur systems do.
Sony has also incorporated their high-end video processing chips into these cameras which increases the speed at which pictures can be taken and processed. The H9 and H7 have ISO3200 which lets you take pictures in low light without flash to minimize blur. Combining the fast processing with new predictive technology Sony is introducing an advanced sport shooting mode to take up to 100 continuous shots at frame-rate of 2.2 pictures per second.
For 2007 the H9 and H7 are the only cameras released by Sony that feature a new technology called NightShot which apparently uses infrared technology to capture pictures in situations with almost no light. Other features include a tilting LCD lens, recognizing up to 8 faces, and a high definition output port (custom cable sold separately) to view images directly on the TV.
Differences between H9 ($480) and H7 ($400)
The H9 features a 3" tilting LCD screen, while the H7's screen comes in at a smaller 2.5" and does not tilt.