Rails master version check is broken.

http://github.com/rails/rails/commit/1a5654851e23b081c331bb3a7e0d0f...

Example:
ruby -v
ruby 1.8.7 (2009-12-24 patchlevel 248) [i686-darwin10.3.0], MBARI 0x6770, Ruby Enterprise Edition 2010.01

rails s
Rails 3 requires Ruby 1.8.7 or 1.9.2.
You're running 1.8.7 (2009-12-24); please upgrade to continue.

Solution 1:
explicit version conditions

   unless %W{1.8.7 1.9.2}.include?(RUBY_VERSION)
     abort ...

   end

Solution 2:
some sort of range conditional but im not sure the criteria.

   if ruby_release < '1.8.7' || (ruby_release > '1.8.8' && ruby_release < '1.9.2')
      abort ...

   end