Samsung's Galaxy S line of flagships traditionally launches in Q2 - the original launched in June, the sequel in April and the Galaxy S III in May. What about the S IV? A post on Samsung Lebanon's Facebook account points to May for the Samsung Galaxy S IV launch date.
While we know better than to take anything coming from a Facebook page for granted, we wouldn’t be the least bit surprised if the Galaxy S IV has a May launch (it's when the S III launched after all).
Earlier, Reutersreported that the S IV will be launching in April, which doesn’t seems slightly less likely, given the enormous popularity the Galaxy S III and Note II are still enjoying.
That's for the launch date, when the new phone might be announced is a completely different matter. The first two of the line were announced a few months before launch, while the Galaxy S III was announced and launched in May. We expect the forth Galaxy S flagship to follow the footsteps of its predecessor, though, and only go official a couple of weeks before it hits the shelves.
Now if everyone could please stop with the CES/MWC announcement rumors - it's simply not happening. What we might see at CES though, is tech that will go into the Galaxy S IV like the rumored 5" 1080p Super AMOLED or a Cortex-A15 based chipset, which are also going around the rumor mill.
Note: Samsung Galaxy S IV concept render by Rozetked.