Nikon's new J2 isn't radically different than its predecessor, but it did bring with it a new toy for them both to play with. The WP-N1 can accommodate either the J1 or the J2 with the 10-30mm lens attached.
While the J-series is a decidedly consumer-level affair, the WP-N1 is a serious underwater setup. It will keep water out to a depth of 40 meters, or 131 feet. That's significantly deeper than most rugged compact cameras will go.
You can maintain full control over the camera and has a cold shoe on the top for attaching lights or the rumored Nikon harpoon launcher some sites are saying we might see at the Photokina trade show in September. [Editor's note: Not really.]
Because it's a serious rig, however, it comes with a serious price tag of $750. That's a full $200 more expensive than the camera itself. That's actually not uncommon, as some DSLR underwater housings easily climb into the thousands, but with a consumer-level camera, that becomes a harder sell.