The IRB has agreed to allow Argentina to join an expanded Tri-Nations competition, but it may take a decade for them to be ready.
By far the majority of Pumas play for Northern Hemisphere teams during the year; hence the state of domestic South American rugby is relatively weak. It could take ten to twelve years for a strengthened Argentinean competition to become attractive enough to keep their best players at home. Any Pumas joining a Southern Hemisphere competition whilst still playing for their Northern Hemisphere teams would contravene the 10-week rest between seasons rule.
So, whilst the prospect glitters in the distance, there's a great deal of work to do before a 4-nations competition below the Equator can become a reality.
Shame really.
