Microsoft's Skype entity already offers a product called Skype WIFI (link) which allows you to buy WIFI access in millions of locations by the minute. A barebones webpage now may indicate that Microsoft has bigger plan for it's WIFI resale business and may be branding it Microsoft WIFI (link).
The service (purportedly) will offer access to its millions of WIFI access hotspots to Office 365 Enterprise subscribers, Surface 2 owners or buyers of the Work & Play bundle.
The DNS lookup of the website seems to indicate that it belongs to Microsoft so I am assuming it is legitimate but it is still very sparse and missing tones of information. Based on the info it does contain, it looks like this service will continue in the path started by Skype WIFI where Microsoft will resell WIFI hotspot access belonging to other providers such as Boingo, XFinity WIFI, BT and more. And yes, it does look like a global service.
We don't know the model they will use. Will it be a subscription based model, a pay-per-use model or a hybrid? Will some access time be included in the base subscriptions?
We do know, based on the website that they will have apps for most platforms including Windows, Android, Mac OS X, iOS and Windows Phone. Skype WIFI also offered an app for these platforms but also included one for Linux (which the Microsoft WIFI page does not mention right now).
At this point that's all we know but I'll keep watching this site and report back when things develop further.