A couple of day ago, a rumor appeared that the next S5 will have a waterproof version. Some say that Samsung expects to sell version to 20-30% of all S5 customers. This expectation comes from the need to sell more waterproof and rustproof mobile devices. An anonymous source confirmed this information and added that it is possible that a vast majority of Samsung devices in 2014 will be waterproof.
There is another sign that this rumor can be true. Samsung just called it's 5 million LDS antennas order. A LDS antenna is usually onto the back plate of a mobile device. It is very thin, but it doesn't allow the device to be waterproof. Instead, Samsung will order IMA (in-mold antenna). Devices with IMA can be waterproof and are thicker.
Daesan Electronics is a tech manufacturer which creates IMA antennas that are almost the same dimension as a LDS antenna.So, maybe Samsung will use this technology for the new S5 Active. It is said that there will 5 million S5 Active devices initially, with further production to be based on demand. We don't have a launch date yet, but it's rumored to be around May.