These products haven’t been announced yet, but the “mobileleaks” YouTube channel has posted a promotional video for them. Unlike something like an Olloclip, these aren’t just lenses; with a full CMOS sensor inside, they’re more like cameras that require a smartphone for control.
With people increasingly shooting photos on their phones rather than with a dedicated camera, Sony’s concept seems quite clever. It appears to be only a little clumsier to attach than an Olloclip, though, it is substantially larger. It’s not going to be cheap, but it’s a Sony camera, so it’s probably going to be worth it.