Two hundred must be a magic number for Apple engineers and executives – it’s the number of new features to be found in OS X Mountain Lion, due in July, and it’s also the number of enhancements Apple has announced for iOS 6, which was unveiled today at the WWDC keynote address.

iOS 6 will come this fall, supporting iPhone 3GS or higher, 2nd-generation iPads and newer, and the fourth-generation iPod touch.

Siri improvements are a centerpiece of iOS 6 changes. Siri now knows about sports, has more information about restaurants thanks to Apple’s partnership with Yelp and OpenTable, has more information about movies thanks to integration with the Rotten Tomatoes Web site, and can now launch Apps.

A new feature called Eyes Free is a joint effort with car makers including BMW, GM, Mercedes, Jaguar, Audi, Toyota, Chrysler and Honda, to integrate Siri support. So when you’re in your car you can use hands free systems to communicate with Siri, to keep your eyes on the road and your hands on the wheel. All the car makers are promising support for Eyes Free in the next year.

English and French support for Siri is coming to Canada, along with support for Spain, Mexico, Italy, Switzerland, and Korea.

Siri will also be supported on the new iPad with iOS 6 – an omission many customers were uphappy about when the new iPad was introduced. Older iPad owners (original iPad, iPad 2) are out of luck.

Facebook is now integrated into iOS 6, similarly to Twitter. You sign in once and use those credentials whenever you post. You can post pictures from Photos, info from Safari, location data and so on. It’s a public API, so other iOS apps will be able to use it. Brace yourself for a lot more Facebook chatter from iOS friends in the coming months.

Facebook support has also been integrated with the App Store. Tim Cook wasn’t lying at AllThingsD when he said that Apple was looking for new ways to integrate social networking.

Another new feature lets you control how you respond to incoming calls. You can be reminded later or send a text message back – better for circumstances where you can’t take a call at that time.

There’s also a new “Do Not Disturb” feature that mutes push notifications and keeps the screen dark. You can screen calls or even set the phone to prompt you if someone calls repeatedly.

Facetime works over cellular data in iOS 6 – presently it’s relegated to Wi-Fi. Facetime also unifies phone number and Apple ID – you can answer calls on your iPhone, iPad or Mac.

Maps have been completely redone iOS 6, replacing the Google Maps-driven feature in previous iOS releases. The map cartography has been made by Apple. It includes 100 million business listings around the world, real-time traffic data, turn-by-turn navigation (finally), and if you hit slow traffic, it’ll try to reroute you. The new Maps app is integrated with Siri, so you can ask questions en route without getting distracted by tapping the phone. A 3D view shows you vector renderings of buildings and other structures along the way, but one standout feature is called “Flyover.” Flyover shows you detailed renderings of terrain and structures, almost photographic-quality.

Other new features include enhancements to Game Center, support for “Made for iPhone” hearing aids, personal and work e-mail signatures, and a “Lost Mode” – you can send a phone number to your misplaced iOS device; if anyone picks it up and taps the screen, the phone will call that number.