My current travel machine is a 2011 MacBook Air. It still works, but battery life is a fraction of what it once was. It's not dead yet, but it's ... hanging on there. I could wait for whatever Apple's going to announce at WWDC, but I'm going to be on the road a bunch this summer, making it attractive to set up a new machine beforehand.

The old machine's specs ain't bad. I maxed it out when I bought it, which means 256GB of Flash, 4GB of RAM, and a dual core i7. Most of my travel needs boil down to running a browser and checking my email, but I also use this machine when I'm teaching my class for live coding (with IntelliJ, and it's sometimes a bit slow) as well as when I'm doing photography (i.e., running Lightroom). I want a faster machine.

Reasons to just buy a new MacBook (12" Retina):

Maxed out, a 12" MacBook is smaller and lighter, with twice the storage and twice the memory and... a slower CPU but with a faster burst mode? Also of note, you can finally buy a USB-C adapter that does all the things I'd want: passthrough charging, HDMI, SD card, and multiple regular USB ports.

Get it now, get it set up, and I'm ready to hit the road. Also, for my teaching, the MacBook gives me a good "lower bound" on student machine speeds. I'm spoiled by my MacPro desktop box.

Reasons to wait:

The MacRumors buyer's guide is a sea of "don't buy / updates soon" signals. Also, the 12" MacBook is a good deal slower than I'd desire for pushing photos or running a dev environment. That sort of use case generally nudges you toward the MacBook Pro line, which may or may not have some super-cool upgrades coming. I care a good deal about travel weight, so a computer that weighs like a MacBook Air and performs like a MacBook Pro is my dream and the rumors suggest it might be coming.