They already make parts for gaming computers, produce gaming laptops, and they have already started to produce all in one computers in the MSI factories. A true gaming PC was not yet on the product list, untill the MSI Nightblade was introduced. A proper Game PC, sort of, as for now it is only available as a barebone system and will need to be finished either by yourself or with help of your computer shop. .
The barebone PC is working on a come back, especially due to the popularity of mini PC's like the Intel NUC and the Gigabyte BRIX, and last but not least the barebones made by Shuttle we have seen more diversity and choice coming into the market. The Nightblade is a lot bigger and more extreme than the small Gigabyte or Intel machines, and competes directly with the high end models made by Shuttle. .
Shuttle chooses to use their own bespoke form factor motherboards in their barebones, MSI keeps thing more standard ans has used a slightly adapted version of their own Z87i Gaming AC ITX motherboard. A small system, but with enough possibilities to turn it into quite a powerful machine. The motherboard itself is already quite interesting, as it has a lot of overclocking features as standard. The OC button on the front of the case for example starts the OC-Genie wizard for easy overclocking. The Audio Boost headphone amplifier is also present on this version of the motherboard and the Nightblade sports the very extensive BIOS with all the normal options found on any other MSI motherboard. So the system might look compact, but you get what you can expect from MSI, a very complete base to start without having to make compromises in features..