The big issue for the World Cup is where the opening game and semi-finals and finals are to be held.
The opening game is already been decided as a double header -- including England vs Australia -- at Cardiff's Millenium Stadium. This is a big mistake because the Welsh will not show up in sufficient numbers to even quarter fill the stadium and not enough English will show up to fill it. They will be lucky to 35,000 there (i.e. half full), which will be a PR failure for the tournament. Had the opening game Australia vs England been held at Wembley then they could have counted on at least 50,000, and quite possibly many more.
One of the semi-finals or the Final has to be at Wembley, otherwise the game will have failed to use the World Cup to create any momentum for growth of the game in England.