Apple today seeded build 14B23 of OS X 10.10.1 to developers, one week after seeding the first OS X 10.10.1 beta, build 14B17



From MacRumors:

While it is unclear what improvements the first update to OS X Yosemite will bring, there are several bugs in the operating system including a major Wi-Fi issue that has caused connection problems for a number of users. Apple is asking developers to focus on Wi-Fi, Exchange accounts in Mail, and the Notification Center.

  Apple Seeds Second Beta of OS X Yosemite 10.10.1 to Developers