During WWDC, we should see Apple introduce iOS 8 with the new Healthbook fitness tracking app. And we also are getting a surprise. According to a report published on Wednesday, Apple is rumored to be introducing new hardware during the conference. That could mean anything, although earlier this year there were rumors that Apple would introduce the long-awaited iWatch during WWDC. That would make a lot of sense. If Healthbook is going to be revealed during the conference as the app where all of your medical metrics are stored and analyzed, you would expect to see Apple show off the hardware involved in capturing those readings. And that is where the Apple iWatch comes into play.
As far as the Apple iPhone is concerned, back in January, one analyst called for Apple to introduce a 4.7 inch Apple iPhone 6 and a 5.7 Apple iPhone phablet at WWDC. According to this rumor, the Apple iPhone 6 would be released shortly after the developer conference, with the larger iPhone phablet getting released later in the year. With other rumors calling for the new Apple iPhone model (s) to be introduced later this year, we will just have to wait to see what the mystery hardware announcement will be, if indeed there is one. Luckily, we don't have much long to wait.
source: WWDC via 9to5Mac (1), (2)