Page design feedback: You should make the "Free Trial" link more prominent (make it a button with a bright background). Bump up the line-height on all the text; it looks too crowded.

Features list needs to give more specifics about RAM, disk space, bandwidth, etc., not just a list of pre-installed software (especially things like Express and Backbone that are trivial for me to bundle with my app when I upload it).

The bullet point about "We don't make you go through a proxy" is useful. You could also brag that WebSockets work—last I checked, this is a big drawback on Heroku.

Is there a reason you refer to Node as "n*d." on the front page, and "nod." on the features page?