I've pre-built w/ the sportdb Ruby gem  worldcup.db - an SQLite
database - using the open public domain data sets  including all 20
world cups, that is, from Urugay 1930 to the upcoming Brazil 2014
You'll find the release on GitHub  (~ 1 Meg).
Note: As always you can build yourself an up-to-date version using
rake e.g. issue
$ rake build DATA=history
Use the models shipping w/ sportdb to use the data in Ruby. Example:
w = Event.find_by_key!( 'world.1974' )
assert_equal 16, w.teams.count
assert_equal 38, w.games.count
assert_equal 12, w.rounds.count
Or as an alternative start up the builtin (HTTP JSON API) web service e.g.
$ sportdb serve
PS: Upcoming Events => Int'l Open Sports Data Hackdays (Fr+Sa
May/23+24) - Join Us