Install Latest Ruby (2.0.0) with RVM

Step 1. $ rvm list known
# MRI Rubies
[ruby-]1.8.6[-p420]
[ruby-]1.8.7[-p358]
[ruby-]1.8.7-head
[ruby-]1.9.1[-p431]
[ruby-]1.9.2-p180
[ruby-]1.9.2-p290
[ruby-]1.9.2-p318
[ruby-]1.9.2[-p320]
[ruby-]1.9.2-head
[ruby-]1.9.3-preview1
[ruby-]1.9.3-rc1
[ruby-]1.9.3-p0
[ruby-]1.9.3-p125
[ruby-]1.9.3[-p194]
[ruby-]1.9.3-head
ruby-head

 seems ruby 2.0.0 is not in rvm's known list

Step 2.  $ rvm get stable      # to update rvm known list

now repeat step 1 you will get ruby 2.0.0 in known list

Step 3. $  rvm install 2.0.0