Apple Update: Mountain Lion

Apple has just released a quick guide that explains how to update the computer into OS Mountain Lion.The new OS is rumored to be released in July. Below is the list from any computer that can be upgraded to the Mountain Lion: 
-iMac (mid 2007 or later)
-MacBook( end 2008 , early 2009, or later)
-MacBook Pro (mid or end 2007 or later)
-MacBook Air (end 2008 or later)
-Mac Mini (early 2009 or later)
-Mac Pro (early 2008 or later)
-Xserve (early 2009)
the statement is unfortunately Apple did not announce the reason for the device other than those mentioned above can not taste the Mountain Lion. However according to Ars Technica, the graphics sub-system on some 64-bit system is the problem, where the Mountain Lion can not operate on devices that are still operating with 32-bit GPU drivers.
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