you want to know the commits that never made it into svn

not_in_svn.rb

# usage:
# git log | ruby not_in_svn.rb | less
# license: Apache 2.0
# copyright: J Chris Anderson 2011
# this might be too trivial to copyright

buffer = []
while(line = gets)
  if line.match(/^commit/)
    puts buffer, "\n" unless buffer.any? {|x| x =~ /git-svn/}
    buffer.clear
  end
  buffer << line
end