I don't know about spreading themselves too thin, I mean, are they gonna' be using existing development teams, who'd normally work on PS4 games and such, to make these mobile games, or are they gonna' be expanding and opening new, smaller development teams to focus on mobile? And as of now, the games are only gonna' be released in Asia, so it's not like their western development teams are gonna' have to halt production on whatever to jump on the bandwagon... not yet at least anyway, lol.
The XBO has indeed outsold the PS4 in the UK in September, although it's nothing to brag about when you consider how many consecutive months it was the other way around, and with the release of PS4 Pro we'll probably see the positionings flip-flop again... and then again when the Scorpio is released. Obviously people were expecting the PS4 to outsell the XBO in the US/UK again once the PS4 Slim released, but it didn't really offer anything new, whereas the One S has the advantage of a 4k bluray drive, which is apparently a pretty big selling point, since from what I've been told (Not done any research on this), it's now the cheapest 4k bluray player you can buy, much like how the PS3 was the cheapest bluray player at the time of release...
Not tried any form of VR myself, was actually gonna' try the Playstation VR a couple of weeks back, they had a booth set up in Meadowhall, a shopping center near me, with some demos, but it would've meant missing my train home, and I was pretty tired, so decided to give it a pass lol... the quality of the games seems to be pretty divided in my opinion, I'm seeing critics give both impressions of good and bad with it, but from people I know online that've used it, the majority of them really enjoy the experience. Like I said, I've not tried any VR, but for the price you're paying you can't expect the definitive experience, that'd come from one of the PC headsets surely, although I'm still interested in giving Playstation VR a go sometime in the future depending on the support it receives.
One thing about their VR that kinda' bugs me though is that, as far as I'm aware (Again, not done any research on this), it doesn't work with PC... obviously there's the argument that if you're playing on PC you want a better experience, but it'd be a lower entry point for people on the platform, and would boost both the sales of the device itself and the development of VR games due to a larger userbase for developers to release to...