The Samsung Galaxy S4 has leaked a few times before but this slip comes from Lee Keon Hyok, Senior Vice President at Samsung Electronics who talked to BussinesWeek.
Apparently, " the Galaxy S4 doesn't come out until late April.It's fast, has a big bright screen, and will probably be another huge hit for Samsung, as will the S4 mini that will go on sale soon after".
That's not a lot to go on, but at least if confirms that Galaxy S4 mini exists and we're not looking at a random Galaxy model.
From some unconfirmed information the Galaxy S4 mini will have a 8MP camera that will capture HD video(possibly 1080p) and will have a front-facing camera of unknown resolution.
The Galaxy S4 mini chipset will pack just 1 GB of RAM. The internal storage options are 8GB, 16 GB and 32GB with a microSD card slot. The estimated price for the Galaxy S4 mini is $450.