Samsung are gearing up for the release of their next Galaxy S device. The S4 has seen huge popularity all over the world and Samsung are pushing out the kernel source for the S4 variants GT-I9500/GT-I9505/SGH-I337M. You can take a look at the source yourself with the links below(may be a slow download). The Galaxy S4 is set for release on the 26th/27th of April with some countries expecting it to early May.
Source: Samsung (i9500), (i9505), (I337M)