Love the concept. Casual use of VMs-as-if-they-were-documents is a great trend that still has a lot of potential. (StackRocket/Blueprint/Vagrant/etc could possibly benefit from a Ninite-like visual interface for bootstrapping dev/server VMs.)

A couple landing page nits:

• it'd be helpful to have some extra details/screenshots for people without flash to play the demo video

• lots of things on the landing page seem like they should be clickable to get started, but aren't. For example, 'Create a dev stack' and 'Make a stack, customize it' button-like areas. I bet using a click-analytics heatmap you'd see a lot of stray clicks on those.