Looking to upgrade my rig. DSLR's and HD video cam technology is converging. The thing I like most about my current point-and-shoot is that I can do both stills and video easily. The most common subjects I shoot are sharks, other large pelagics, and wrecks. Second is macro life. My current P&S has bayonet lenses which I can change underwater - pop on the dome for super wide-angle, take it off for medium or zooming in, and put on a macro magnifier for close ups. This has been a major plus. Here are 2 vastly different setups I am considering. Strobes/lights and housing are TBD. I have tested both, granted non-scientifically, and both delivered outstanding results. I have not had the opportunity to take either one underwater.
Sony HDR-CX520V (specs here) 1080p HD video and 12.1 megapixel still images.
Canon EOS Rebel T1i EF-S (specs here) 15.1 megapixel and 720p/1080p video
What is your opinion/experience with DSLR video? How about video cams with still capability? What direction would you go? Alternative suggestions?
Most important is image quality, followed by future expansion capability (non-obsolete), and then cost. I would rather spend some extra $$$ to get the "right" base setup now rather than cut corners and have to rebuild from the ground up later.