And it's testament to the rivalry between these two sides that he does so.
Leinster claimed the Heineken Cup last year but were denied double when they lost out to Munster in the Celtic League final last year - and it hurt.
Throw into the mix the fact that 22 of Ireland's 30-man World Cup squad ply their domestic trade for one of these two sides and most of those will be on show in Friday's RaboDirect PRO12 clash - and O'Kelly believes the heat is cranked up a further notch.
"The thing that strikes me most about the games between Munster and Leinster is the sheer intensity," said O'Kelly, who has announced his involvement in the Heroes Rugby Challenge as part of the Northern Hemisphere team.
"When we got the better of them in 2009 at Croke Park I think that was my greatest day in rugby, better than anything achieved for Ireland and that's saying something.
"The crowd was electric, really electric, it was comparable to playing Test rugby and it always is when these two teams play against each other.
"A great deal of people from Cork and Limerick live up in Dublin and they come out in their droves for occasions like this, provincial rugby still means a lot to people in Ireland.
"The quality of the match will be immense as well. There are the World Cup players returning and I'm sure they'll be relishing getting back into a match like this so soon."
While all of Munster's World Cup big guns have already got one RaboDirect PRO12 game under their belts since returning from New Zealand, a number of Leinster's have not.
Ronan O'Gara, Paul O'Connell and Keith Earls all featured in the win against Aironi last weekend whereas Rob Kearney, Jamie Heaslip, Shane Jennings, Sean O'Brien and Gordon D'Arcy are all set for their first domestic appearances of the season.
Ireland captain Brian O'Driscoll has not even made the matchday squad in what appears a bold move by Leinster boss Joe Schmidt - but it's one that has O'Kelly's backing.
"I think Joe is a very shrewd boss and I hopefully it will prove a shrewd move," added O'Kelly, who ended his Leinster career with 183 appearances to his name.
"Some players take longer to come back than others. It does seem that Leinster are drip-feeding their players back in a bit more than Munster and it's a brave move but one that Joe feels will work.
"And you can't go dropping 14 players who have been playing while the World Cup is going on. You have to reward the ones that played and keep faith. I think Joe knows what he's doing."
Heroes Rugby Challenge, Saturday 3 December 2011 at Twickenham Stadium, kicks off at 1630. Ticket prices start at £30 for adults and are available through Ticketmaster www.ticketmaster.co.uk or by calling 0844 847 2492
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