All You Need to Know About the Ongoing Rugby World Cup

The 2015 Rugby World Cup is underway in England, twelve years after England won their first and only World Cup in Australia.

This is the eighth Rugby World Cup, and will last for a total of six weeks till October 31st. 13 Stadiums including Wembley, Manchester, Millennium (Cardiff), Olympic (London), Villa Park (Birmingham) and St. James Park (Newcastle) will host group and knockout games over this period. The final will be held at the Twickenham Stadium in London. Traditional favorites and defending champions New Zealand are once again at the top of the list, followed by Australia, South Africa, France and England. 

The World Cup has 20 participating nations, and the list is the same as the 2003 World Cup. Only Uruguay has replaced Russia from the 2011 World Cup. There are 5 groups of 4 teams each, with the top two of each group slated to proceed to the quarterfinals.
England has been the only team from the Northern Hemisphere to win the World Cup and break the stranglehold of Southern teams like New Zealand (2), Australia (2) and South Africa (2). 
New Zealand won the first ever World Cup in 1987. Australia won in 1991, South Africa in 1995 (on which the film Invictus was made), Australia again in 1999, England in 2003 (they defeated Australia with a famous Johnny Wilkinson kick), South Africa in 2007, and the All Blacks in 2011, where they defeated France narrowly in the final by 8-7. 
This World Cup has already seen a major upset, with Japan defeating South Africa in the group stages 34-32. A few days later, Scotland thumped Japan 45-10, which only proves that there are no early favorites yet, with every team trying to overcome the rust to make it to the last 8.
Argentina and Samoa are the dark horses in this tournament. 
France is the in-form team, and is favored to reach the final.
Likely quarterfinal scenarios read as: Group A winners Australia could face Group B runners-up South Africa. Group B winners Scotland could face Group A runners-up England. Group C winners New Zealand could face Group D runners-up Ireland, while Group D winners France could face Group C runners-up Argentina. This way, the top 4 ranked nations (NZ, SA, AUS, FRA) could avoid quarterfinal clashes. 
France has reached the final 3 times without a single win. This could just be their year.
Japan will host the next World Cup in 2019 – the first nation in Asia (or first nation outside the top 4) to host the tournament.
The All Blacks have won 76% of their Test Matches, and were the 2014 World Team Of The Year. They have held the no. 1 ranking since late 2009. Their 8-7 victory in the 2011 final was the narrowest victory in the lowest-scoring final in Cup history.
New Zealand World Cup winning Captain Richie McCaw is the most capped player in Rugby history, and is the only captain to lead his team more than 100 times onto the field.