I bought the gopro hero hd and i emailed them after discovering the focus problem underwater. This was their response:
Due to the curved lens of the waterproof housing for the HD HERO camera and standard def Wide HERO cameras, you do get a slight loss of sharpness/focus to underwater images. In video mode with the standard def camera this hasn't been very noticeable due to the lower resolution. With the HD HERO camera this becomes more evident at the higher resolution. Our developers are looking into whether we can possibly offer a different housing or housing lens in the future to correct this issue.
I should add that besides this, the camera is incredibly cool. Tiny, can shoot for long periods of time with 8 GB SD card, and above water you can do things with it that you just can't do with any other hd camera out there. So with any kind of fix to the blur issue, everyone is going to want one. The only other issue is the files are HD Mp4s that can choke up the average computer so I have been encoding the files all to friendlier hd formats such as DVCPRo HD (i'm a mac guy without one of the new intels) which is a format that looks awesome but can still play on an older laptop.