Three of the semi-finalists are previous winners of the title, with the presence of Munster raising the unprecedented prospect of the holders retaining the trophy.
Meanwhile, the progression of Glasgow Warriors to the play-offs could lead to the possibility of a Scottish team winning the competition for the first time ever.
Both Munster and Glasgow have been drawn away and will have to overcome 'home field advantage' if they wish to progress to the grand final and the head-to-head for the biggest prize of all, the Magners League title, on Saturday, May 29.
Everything is set for a scintillating weekend.
MAGNERS LEAGUE - SEMI-FINALS:
Friday, May 14 -
Ospreys v Glasgow Warriors, Liberty Stadium, 7.05pm (live Setanta Sports Ireland/BBC Wales)
Referee: George Clancy (Ireland)
Assistant Referees: Dudley Phillips, Leo Colgan (both Ireland)
Television Match Official: Bertie Smith (Ireland)
Saturday, May 15 -
LEINSTER v MUNSTER, the RDS, 8pm (live Setanta Sports Ireland/S4C)
Referee: Nigel Owens (Wales)
Assistant Referees: James Jones, Nigel Whitehouse (both Wales)
Television Match Official: Hugh Watkins (Wales)