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.

Perhaps in the interim you could have a new battery installed in the old MacBook Air. That would potentially also improve its resale value once you buy a new machine.

I also await the upcoming 2016 MacBook Pro refresh as my own MacBook Air (maxed out specs, 2012 model?) struggles with my daily computing workload. CPU utilization hovers circa 50% all day and often slams into 100% for many seconds for video clips, app startup, etc.

For the Summer why not pickup a Chromebook if all your needs are a browser and email? And then grab the shiny new offering in the Fall.

Part of the summer will involve vacation of various sorts, which means grinding through lots of pictures, which is one of those CPU-slamming sorts of activities. I guess this has me leaning toward "live with it until WWDC then order right away".

Replacing the old battery might be useful, but it's not critical. I'll basically keep this machine in reserve until it dies, then trash it. (My 2008 MacBook Air was serving as a print server until its battery inflated, distorting the aluminum case. Right, shut that thing down before it catches fire.

Another thing to consider is... what is your financial situation? Would buying the new computer now, then buying the new model when it is available, be a serious strain monetarily? Are you trapped in the mindset of "What is the most fiscally responsible thing to do?" as opposed to "What would most enhance my productivity even if it costs more?"

If we waited for the absolutely optimal time to buy from a fiscally conservative point of view, we'd still be running Windows 3.0 on a '386 with four megabytes of RAM, because there will always be something newer and shinier just over the horizon.

IF you are in a position to do so, you should buy the new computer now and enjoy it, sell it when the newer, shinier one comes out, and swallow the monetary loss. A year from you you'll never miss that $800 (or whatever) and meantime you'll have had the joy and productivity of the current hardware.

tanstaafl.

Spend, or do not. There is no try.

May the forth be with you.

I'm tormented by the Ghost of Steve Jobs.

Based on Geekbenck scores, the CPU performance will go up by about 30-40% with a 2016 MacBook with the upgrade to the 1.3GHz option compared to your current 2011 MacBook Air. Between that and the much faster SSD, it may fit your needs well factoring in the travel aspect.

I'm a Luddite. Upgrade when you can't do the stuff you want to do easily. (My 12 yo son just got a new/used computer to replace the 10 yo thinkpad that had a failed battery and a failed touchpad & eraser. I figured it was time. Now he's using a 6 yo thinkpad...)

As tanstaafl said, there's no "right" time - just your time. And time is money...

-jk