On Monday, Apple released the first beta of OS X Yosemite 10.10.1, the forthcoming first update to
Yosemite. This first beta is the first to arrive after the release of OS X Yosemite on October 16. The new build, 14B17, can be obtained by registered developers through Apple's Software Update. Apple is asking developers to focus on Wi-Fi, Exchange accounts in Mail, and Notification Center. No release notes have yet been published detailing any changes or fixes present in 10.10.1.
The updated beta is available for developers through the Mac App Store's software update, or from the Apple Developer portal. The new beta is also available for AppleSeed testers.