hi!
when the site loads, the facebook buttons need some time more to load (of course). but they don´t seem to be in a container, so some elements jump when the buttons are rendered.
the signup button is very hard to find. you could make it much bigger "web 2.0" style and with green background (which is good for conversion rates).
i´d replace "watch the video" with a big play button in the middle of the image. this way, more people will watch it.
the signup form:
i´d mask the rest of the site when it´s showed, to make clear that the user can´t do anything else right now.
the captcha is centered now, but the text fields not. i´d right align the captcha.
when first opening the signup form, the error message for the full name is shown in pure red. for me the error should only be shown when the user tries to submit the form. and you could use a more decent color for the error messages.
add a * to all required labels (and "fields with * are required), so the users knows which are required. right now he has to wait for error messages.
the checkbox and notice texts (at the bottom) would look better if they were all aligned with the text fields.
i´m not quite sure, whether purple is the right color for the notice text.
for the checkbox: it´s a lot clearer if there is first the checkbox and then the label for it. (i personally try to always use wordings with I instead of you. feels better somehow)
i like the js validation when the user inputs the needed information. - well done!
hopefully i was not too hard to you :)
martin