(Sorry for late reply, work and all)
Well I'm programming. I'm also known to have a huge amount of tabs opened but with the 2015 13"
2,9 GHz Core i5 -8GB, I can tell you it's slow even with 35 as I speak.
For a machine that is THAT expensive (2200$ on that side of the atlantic), it's just not acceptable.
What I'm expecting ? A revolution, something incredibly thin and powerful. Or why not, upgradable (stupid expensive ram). I'm expecting of course the latest gen of CPU (which we won't have) and a powerful one at it.
I'm expecting to be able to run a server and have 100 of tabs in my browser (don't ask) without the machine choking on it. That's about it.
Also, they did change the fundamental nature of laptops (and OSes). Unibody, thinness -is that a word ?- which gave birth to ultrabooks, Retina screen, great battery ...
I don't know I expected an oled screen, not an oled bar ! Something really cool, really powerful. Instead it seems we'll have a wet cracker, but hey, let's wait and see.
If it proves to be disappointing, at least we'll have great Windows machine to get to. It's going to be a pain to transfer all my stuff and learn new tools but c'est la vie.