What machines will OS X 10.10 (Yosemite) run on?

Business Insider lists the following Macs as compatible :

• iMac (mid-2007 or newer)
• MacBook Air (late 2008 or newer)
• MacBook (Late 2008 Aluminum, or Early 2009 or newer)
• Mac Mini (Early 2009 or newer)
• MacBook Pro (Mid/Late 2007 or newer)
• Mac Pro (Early 2008 or newer)
• Xserve (Early 2009)

From Wikipedia, regarding the Developer Preview:

The OS X v10.10 Developer Preview is compatible with all Macs that are capable of running OS X Mountain Lion and OS X Mavericks.

The full list of compatible models from the release notes:

• iMac (Mid 2007 or newer)

• MacBook (Late 2008 Aluminum, or Early 2009 or newer)

• MacBook Pro (Mid 2007 or newer)

• MacBook Air (Late 2008 or newer)

• Mac Mini (Early 2009 or newer)

• Mac Pro (Early 2008 or newer)

• Xserve (Early 2009)