Apple's annual World-wide Developer Conference has recently sold out, after merely 12 hours of ticket sales. This year the event will host 5,000 developers from around the globe, and each ticket cost $1599. That's just under $8M in ticket sales. In 10 hours.
Last year, it took eight days for WWDC to sell out. 8 * 24 = 192, 192 / 10 = 19.2. So tickets sold out 19 times faster than last year. While this must seem like small change to Apple, who recently turned over $26.74B in one quater, it goes to show that developers are still as excited about developing for the iOS and Mac platforms.
If you're a developer and you've not got into iOS/Mac development yet, get involved.