After purchasing my Air (same specs as you, apart from SSD, mine is 256GB), I sold pretty much every computer I had because I just stopped using them. I do a lot of Ruby on Rails and AngularJS development + a bit of NodeJS from time to time. One thing I'd recommend is having an external monitor (preferably somewhere in 24"-27") because 13" IS to small to comfortably work on every day, 8+ hours a day.
Regarding programs, well, apart from your favourite editor I recommend an application launcher (http://www.alfredapp.com/) plus a terminal replacement (http://iterm2.com/). Plus a ton of necessary tools to work with terminal, such as git, homebrew, oh-my-zsh,...
Good luck with your new Air! :)