Not that it's a foolproof indicator for this year but new hardware has absolutely been announced at WWDC. The iPhone 3G is the one that immediately comes to mind but it's far from the only one. I'm pretty sure new Macbooks have been included before.
You're right! In fact, the last iPhone to be revealed at a WWDC was the iPhone 4 in 2010.
And boy was that a release! (discounting for Antennagate)
Edit: And the terrible home button
The iPhone 4 was my favorite "new iPhone", if that makes any sense. The screen was amazing for the time!
The iPhone 4 gave birth to front facing camera as we know it. That was practically nonexistent on any other phone at the time.
Wasn’t the 4 the first one with a “retina” screen? That was revolutionary at the time. Today, we take for granted high pixel density phones, but if you compared a 3GS to the new 4, it was mind blowing.
Yes, it was the first one with a retina screen. The change from the 3GS to the 4 was amazing. Also, the overall design was much slimmer. It seemed like a huge upgrade. Most of the upgrades since have felt much more incremental.