I used to work on a 2011 macbook air with 4gb of ram for years w/ multiple IDEs including unity3d, flashbuilder, xcode and visual studio in a vm open at the sam

I used to work on a 2011 macbook air with 4gb of ram for years w/ multiple IDEs including unity3d, flashbuilder, xcode and visual studio in a vm open at the same time. Given the three years of hardware advances and all the work on Mavericks to squeeze out better performance/power usage I don't think you'd have any problems. The only factors that drove me to the bigger Macbook Pro was the screen and Iris graphics for some light gaming.