MSI is targeting the August time frame. That said, some of the designs are still being tweaked and finalized. All of that stuff takes time, as does distribution, so MSI reckons its custom cards will show up closer to the end of the August.
As for the Mech OC cards, they feature a "minimalist dual-fan thermal design" that incorporates MSI's Torx 2.0 fans. According to MSI, these fans provide concentrated airflow and air pressure for added cooling performance. These cards also sport a brushed backplate.
Interestingly, the design that MSI has been using in one its slides to showcase its upcoming Navi-based Mech OC series is not what the final iteration will look like. Instead, MSI plopped an image of a previous generation Mech OC series card as a placeholder, and that slide has been making the rounds.
The image at the top of this article, however, is what the actual card looks like right now. Barring a last minute change, that is also what shipping design will be. It's a sleeker looking card that, to our eyes, is an attractive piece of tech.
In addition to the Mech OC family, MSI will also be outfitting Navi to its Gaming X, Evoke, and Air Boost lines. Specs and pricing will be revealed at a later date.