From Raspberry Pi Foundation:

Let’s get the good stuff out of the way above the fold. Raspberry Pi 2 is now on salefor $35 (the same price as the existing Model B+), featuring:

• A 900MHz quad-core ARM Cortex-A7 CPU (~6x performance) (Broadcom BCM2836)
• 1GB LPDDR2 SDRAM (2x memory)
• Complete compatibility with Raspberry Pi 1

In stock now at element14.

From Microsoft:

We’re excited to announce that we are expanding our Windows Developer Program for IoT by delivering a version of Windows 10 that supports Raspberry Pi 2. This release of Windows 10 will be free for the Maker community through the Windows Developer Program for IoT... (sign up page)