Nationality is a fairly loose concept anyway. But it must be defined for international sport to work. The supplied definition has a small problem with it though. The problem has arisen in the past and will arise again in the future.

Just to quote the rules again
"Citizenship Rules
The rules in relation to citizenship are as follows;
All athletes of a national team must have the nationality of the country or submit proof that they have been a resident of that country for the previous 4 years. (the residency must be continuous it can not be accumulative)
Dual nationality, Athletes having dual nationality may choose to compete for one or another country, but this choice obliges them for a period of three years as a minimum.
These rules will be in force for the 2008 world championships and be retrospective from 1st September 2006"

If we all just rewind our minds to the early to mid 90s again we might remember that these rules fail to cover the situation in Eastern Europe. This would mean that our Slovenian friends plus any of the former Yugoslavian republics could legitimately be excluded from the world champs. You can't have 4 years residency in a country that has been constituted for less than four years. Perhaps a clause might be in order? This would stop any utter bastard from bringing this up at a later worlds and being technically correct.