I'm pretty thrilled with the announcement. Not announced, was this:
http://www.apple.com/shop/product/MMEL2AM/A/thunderbolt-3-usb-c-to-thunderbolt-2-adapter
That was a major worry for me because I have A LOT of Thunderbolt 2 stuff (2 docks, ethernet, firewire). I'll get native stuff at some point but since these new machines aren't cheap.
And I know there is a general want for SUPREME ULTIMATE POWER here, but my favorite laptop thus far has been my older Air. It was a great size/weight. Seeing the 13" Pro come in at a smaller size is nice. (And I'm not gonna lie, I was hoping for Space Gray and got it.) I would have preferred a dedicated GPU on the 13" model, but I was never holding out hope. Seeing that it can drive a 5K screen was good enough.
My gaming is gonna get gimped a bit but...
http://www.razerzone.com/store/razer-core
That's my preference anyway, then I can upgrade video independent of my laptop. The price is a bit high but I'm paying for a Mac anyway so, that's the nature of the beast.
Last point: MagSafe.
I'm not really going to miss it. When I'm working on my laptop where tripping would traditionally occur, I'm on battery. This was not the case five years ago but even in 2013, I was never sitting while plugged in on my Air. The battery life was just too good. Now? I plug in when I'm at my desk. There's nothing to trip over.
Also a bonus: USB charging means being able to swap power adapters between devices and get quality, non-Apple charging devices too. That's a big win. (Now if Apple would just kill off Lightning, that would rule.)