Apple has announced the corresponding model of the next OS Mountain Lion are scheduled to be released in July 2012.
Models since 2008, such as whether the hardware can support 64bit is the point to approximate.
iMac (Mid 2007 or newer)
MacBook (Late 2008 Aluminum, or Early 2009 or newer)
MacBook Pro (Mid/Late 2007 or newer)
MacBook Air (Late 2008 or newer)
Mac mini (Early 2009 or newer)
Mac Pro (Early 2008 or newer)
Xserve (Early 2009)
- None Found