Is 8GB of RAM needed for Macbook Air?

I'm thinking about getting a Macbook Air, and with SSDs contributing to faster performance, is 8GB of RAM really necessary in a MBA, or will 4GB be enough? I plan on using it mainly for iPhone/Android programming as well as some Photoshop, along with the typical web browsing, paper typing, video watching, etc. Also, I intend on dual booting Windows as well. Any suggestions?