Hey all,
A perennial request from WMF engineers/product people, as well as third-party developers, is an idea of what browsers people are using so we know what we have to support on the frontend side of things.
With Legal/Analytics signoff and +2ing, I've built an exploratory tool at http://datavis.wmflabs.org/agents/ which allows people to look at the most prominently used user agents on our projects - editors, readers, mobile, desktop, whatever you want, we've got it!
(unless you want a pony or something. I can't help with that, I'm afraid.)
To answer the most obvious FAQ questions (read: the ones that have already come up ;p):
"Will this be run regularly?" Not as of this moment. At least, not by me. This is an ad-hoc report in response to an ad-hoc request.
"Who do I go to if I want that to change?" Analytics Engineering has this task on their backlog already.
"Can I have it divided up by [country/operating system/what colour socks the users use/etc]?" An ad-hoc report in response to an ad-hoc request; adding additional dimensions/granularity would require additional legal review and further runs.