The main purpose of this beta release appears to be compatibility with WatchKit to allow developers to test their Apple Watch apps prior to the release of the Apple Watch next year. WatchKit is included in Xcode 6.2 beta, which was also released today.
Which suggests that update 8.2 won't be released to the public for a while; until the watch is ready to ship. Though there isn't any reason they can't come out with another 8.1.x of they decide they need to squash a few more bugs.