Sidhe Interactive has recently announced a World Cup update to Rugby League 2 for PS2, a content focused update rather than a new version of the game. Kudos to Sidhe for dropping this clear assertion in the FAQ -- I couldn't say it any better.
If you did not like Rugby League 2 then in all likelihood you will not like this version, and you should consider purchase carefully.
The title has been popular with League nuts, so a refreshed line up of teams (hello Titans fans), players, stadiums, and 'Twilight NRL Grand Final Stadia', plus a World Cup mode, should mean fans of the sport and the game will have fun playing their own version of the event. No release date yet, but the tournament begins end of next week so I would hope this things lands before the tournament passes by or they'll certainly have missed the window of interest.