I was expecting to choose someone with a more marketing/business/corporate suit profile, but I'm happy to see that instead they did choose not one, but two people who are used to work directly with the products.
Hermen has been the most successful ever PS Studios head, and is doing a great job growing it via hirings and acquisitions. I'm sure he'll continue doing a great job now also in charge of Bungie and the adaptaations to other mediums like movies or tv shows.
Regarding "Studio Business Group, which includes all of PlayStation’s first-party teams" sounds that they created it because they plan to add there more stuff in addition to PS Studios and Bungie. Another hint that in the next coming years they may make some big acquisition (which may be related to mobile gaming, don't get too excited).
Nishino also has a great career and I think he's a great choice to head hardware, accesories, PSN and 3r pàrty relations. He has been at SIE since 2006 (he was in Sony Ericcson too before that), also was in charge of PSN/Sony Network Entertainment (SNEI). And well, more recently he was in charge/overviewed the hardware, accesories, etc. Basically what he'll continue doing.
I think it's a good idea to split the job in half, I assume there's a lot of stuff there and better to have two persons instead of one. It also makes sure that each part has someone in charge always focused on that area, and is someone very experienced on it.