WoW - number of players [URGENT]-{PLZ HELP}

It's next to impossible to answer your question because:
1) Blizzard records the number of subscribers but any individual can have more than one subscription
2) More than one person can play on the same account (very very frequent!)
3) People may subscribe but not play 'each day'. Weekends see the most traffic, Tuesday mornings had the least traffic (which is why it's the maintenance day)
But, having said all that: 11.5 million monthly subscribers in December.