iOS 6 Debut and Mountain Lion Release Date
We already know that Apple plans to release a new version of OS X called Mountain Lion after the company released a developer preview in February. The company may use WWDC as a chance to announce Mountain Lion's release date, according to Bloomberg. Apple has already said to expect Mountain Lion in late summer.
The past two OSX updates, Snow Leopard and Lion, were released in August 2009 and July 2011, respectively. During WWDC 2011 Apple only said it planned to release Lion in July and then officially released the new OS on July 20. Given that WWDC is a developer's conference, perhaps Apple will release the near-final version of Mountain Lion (known as the gold master) to developers. Chances are good it might give a ballpark time frame for Mountain Lion's release, but don't count on a specific release date just yet.
As for iOS 6, again this is a developer's conference, so count on Apple to at least give a sneak peek at the expected mobile refresh.
WWDC Chances: Medium
Just like every year since 2007, there's a new iPhone expected in 2012. What we don't know is when it will launch. Between 2007 and 2010 Apple unveiled its newest iPhone models during WWDC, but then threw that pattern into disarray in 2011 when it released the iPhone 4S in October. The latest rumors suggest the next iPhone will be thinner and faster (as usual), sporting an LTE cellular radio, and perhaps a slightly larger screen. Whatever features the new iPhone has the next Apple smartphone will be an immediate hit, according to a PCWorld/Macworld study. In other news, the sky is blue.
WWDC Chances: Low
Apple Television Set
You can't talk about Apple rumors without mentioning the most popular rumor of them all. Speculation about an Apple television set has run rampant across gadget blogs since the October release of Walter Isaacson's biography of Steve Jobs, Apple's recently deceased cofounder, and former CEO and chairman. The New York Times also fed the flames of Apple television hysteria with a report claiming that Apple would almost certainly release a television set as early as 2013. Given the focus on iOS and OS X, and speculation about new MacBooks, iCloud updates, not to mention iOS 6 and Mountain Lion, an Apple television set feels unlikely for WWDC.
WWDC Chances: Low