Are you happy with it? I've had my eye on Zenbooks for a while. I was about to pull the trigger on one, but have decided to either wait for Haswell, or consider getting a (silly) taichi 31 when they come out.
edit Also, I should add that I did spend the extra money to put a Samsung 840 SSD and an extra 8gb stick of ram in here
It's small, the resolution/screen is great, and has everything I need. I also upgraded the RAM and put in an SSD.
After upgrading to 10gb RAM and SSD, it's a really good computer for developer.