A "waterproof cover" for the Lumia 620 Windows Phone is on its way according to a tweet published by Sander Teunissen, sales manager at Nokia Netherlands. Think back to the waterproof Fujitsu IS12T Windows Phone, but potentially sporting the Nokia brand and ability to take a cover off when it's not required.
Unfortunately details are rather limited on the cover, and no images have been shared so it's unknown as to what the cover will look like. The rating, IP54, states that the cover will be able to protect the Lumia 620 from both dust particles and water splashes from all directions. While you'll not be able to take the smartphone in the bath with you, it'll be more resilient to accidental exposure to liquid.
We'll keep our eyes open for further information.
Source: Twitter (@teunii); thanks, Stanislav, for the tip!