Analysis - Thrilling Six Nations finale augurs well for World Cup

Ireland's Paul O'Connell (R) lifts the six nations trophy after their victory over Scotland at the Murrayfield Stadium , Edinburgh, Scotland, in the RBS Six Nations Championship, March 21, 2015. Reuters / Russell Cheyne

LONDON (Reuters) - A Six Nations championship retained on points difference by Ireland left few clues as to which of the northern hemisphere's leading lights are best equipped to mount a sustained World Cup challenge later this year.

Ireland, England and Wales all have reason to feel confident of a deep run in the global showpiece after a Six Nations that began with a laser show in the Millennium Stadium and ended with fireworks on the pitch in Rome, Twickenham and Murrayfield.