I have a Photosmart C7250. When I plug it into my machine, Windows 7 (release client) autmatically finds drivers for Photosmart C7200 series. Some of the functionality of my 7250 is not available such as automatic double-side printing. Also, instead of printing one page-per-sheet, it prints 2 pages on one side as if it is supposed to be a booklet.
You can either wait till the official Win 7 drivers are released, or follow the workaround in the How To Install Printer Drivers in Windows 7 thread, which is stickied to the top of the Win 7 forum here.
I am an ex-HP Employee. Currently inactive on the forum.