It will be great seeing some dedicated love to the Mac again, and it should be heaven for those in the market for a new MacBook Pro, but I will be left a bit disappointed if there is no new 5K external display or updated iMac design.
The iMac is in good shape spec wise (and still has the best display on the market), but if there was ever a time to unveil a 5K Thunderbolt 3 Display it would be at this event. If they don't, it would likely prove the tech just isn't ready, but Apple has always seemingly been ahead of the resolution game - whether it be the iPhone 4, Retina MacBook Pro, or the 5K iMac.
Sitting around and waiting for Cannonlake and DisplayPort 1.3 which would make this easier doesn't seem like their style because by then, any manufacturer will be able to pump out a 5K display that hooks up via a single cable. Hoping Apple work's it's magic to come up with some way to make this possible now and work well - eGPU in display, custom AMD graphics chip in the Mac, or a custom Thunderbolt 3 pipe...whatever it takes...make it happen!