Sources: Sport24.com, Rugby Times, and Fiji public holidays. Countries in the Pacific take rugby very seriously, and following Fiji's win against Wales, thereby acceding to the Rugby World Cup quarter-finals, it is quite conceivable that a one-off public holiday might be declared in Fiji in early October 2007.
One will recall that in June 2006, a win by the Fiji 7s rugby team at the Sevens Tournament (held in London, that year), would certainly have led to the declaration of a one-off public holiday, were it for the fact that another public holiday was coming up (the Queen's Birthday) within a few days. But, the previous year, in 2005, a public holiday was declared for the then again victorious 7s Fiji team.
This year, another public holiday is also coming up, Fiji Day, on October 8, so the declaration of a one-off public holiday remains uncertain. We will, of course, continue to monitor the situation.
Update, October 1st (Niu FM) Interim sports minister, Lekh Ram Vayeshnoi, said that no doubt there'd be celebrations when the team return home and he's hinted that there could be a public holiday as well.