July 2008: 0 downloads (App Store Launched)
January 2009: 0.5 billion
April 2009: 1 billion
September 2009: 2 billion
January 2010: 3 billion
The App Store took a good nine months to achieve their first billion downloads. And then the 2nd billion took five months. And then the 3rd billion took four. Anyone wanna do over/under on how long it'll take for 4-billion?
Bonus: For anyone Street Fighter savvy (and yes that includes you Terrence), you'll wanna see this: (for everyone else, this is the latest trailer of the up and coming Super Street Fighter 4, showing off new costumes and new Ultra Combos)