Let me tell you my experience.
I have a mid-2013 (Haswell) MacBook Air 13-inch with 8GB RAM, 256GB SSD, and the i7.
I started a post-bacc in CS and have been working as a software QA engineer for almost a year now. My laptop can compile my company's iOS app AND build/deploy the API and database to a virtual machine of Windows (with Visual Studio) - at the same time. I might add that it does this without barely breaking a sweat.
Think about using a VM instead of dual booting. For me it is easier to put a VM on another desktop and swipe over to it when I need it. I use VirtualBox and the performance is pretty decent, plus I don't need to restart or only use one OS at a time.
Honestly, developing on OS X is much more enjoyable for me. I took an advanced Java class and had a great time with the IntelliJ IDE, writing a simple REST API (using Jetty for the web container) as well as a couple other small projects.
You might consider the cost savings of a MacBook Air, as well as the longer battery life. I had one term where I was at school for over 12 hours each day (not 12 hours of solid class, but not enough downtime to commute home). It was insanely nice to carry around a light laptop that didn't require me to lug around a charger.
To be fair, there are some downsides. Not absolutely everything is available for OS X that is available for Windows. For instance I need to use Charles Proxy instead of Fiddler as an HTTP proxy (use it for looking at HTTP traffic). And Office 2011 for Mac is not the same as the latest office for Windows, although you could put the newest Office on your VM/bootcamp partition.
There's a reason I keep coming back to MacBooks, though. The build quality is great and this trackpad is fantastic. I love it so much I use the Bluetooth trackpad at home and at work when I dock my MacBook to larger monitors. I also greatly prefer the OS X terminal to the Windows command prompt.
tl;dr MacBook Air has enough firepower for work and school, plus the design and build are unmatched.