It appears Panasonic took a "why mess with a good thing" approach when it came time to update its top-of-the-line rugged model, the Lumix DMC-TS3.
Its replacement, the TS4, is just as durable, waterproof to approximately 40 feet, shockproof to approximately 6.6 feet, freezeproof to 14 degrees Fahrenheit, and dustproof. To go along with its strong build, there's a built-in GPS system, compass, altimeter, and barometer.
The rest of the camera's hardware--the 4.6x f3.3-5.9 28-128mm Leica lens, 12-megapixel high-speed CCD sensor, and 2.7-inch LCD--seem to be the same as on the the TS3, too, though it looks like it has a new image processor since it can now capture full HD movies in AVCHD or MP4 formats.
Among all of the TS4's shooting modes, of which there are many, two stick out as unusual for a rugged compact. One, it has a full manual mode, giving you control over shutter speed and aperture. Shutter speeds go from 60 seconds to 1/1,300 second, and apertures are f3.3-10 at the wide end and f5.9-18 at the telephoto end. While I'm not sure how useful the aperture control will be, the shutter speed control should come in handy.
The other interesting mode is a Time Lapse Shot, where you can set the start time, interval, and the number of photos to shoot, and the camera automatically snaps photos. When it's done capturing, the TS4 will condense the shots for fluid playback, so you can see things like clouds moving across the sky or a flower opening.
Panasonic also included a Miniature Effect mode and a Panorama Shot that can shoot up to a 360-degree horizontal or vertical panoramic photos by taking consecutive shots and overlaying the photos.
So, basically what I'm saying is that other than the new shooting options (and some enhancements to the GPS), the TS4 is the same as the TS3 and it'll still cost $399.99 when it comes to stores in mid-March.
If you're more of a relax-by-the-pool type or you simply want more protection than your typical point-and-shoot affords you, there's the TS20. It's waterproof to approximately 16 feet, shockproof to about 5 feet, freezeproof to temperatures as low as 14 degrees Fahrenheit, and dustproof.
The rest of the camera seems less impressive: 16-megapixel CCD sensor, 4x 25-100mm optical zoom, and a 2.7-inch LCD. It'll shoot 720p HD-resolution MP4 movie clips and has a bunch of Panasonic's creative shooting options, too.
Again, nothing terribly exciting, but it's at least priced well at $179.99. Look for it in late February 2012 in orange, blue, black, and red models.