Hi Bryan,
Your design is looking great, just a couple of ideas to ponder:
~ Responsive design is great for mobile and desktop, it might be a worth looking at some of the in-between layout, between 501px and 767px, to keep the consistent high level of layout.
~ I'd check out your javascript to make sure the success message pops up on a successful form submission.
~ Lastly, it might be worth having a look for a regex that has a better coverage (that catches emails like erree@df
).
Great stuff on the whole mate, just a couple of things to consider :)