You might as well put up a sign-up box on your home page, to start collecting emails. Then when you launch your beta, you'll have a set of customers ready!
I have no idea why everyone decided, all at once, that scroll bars should be invisible by default. The presence of a scroll bar communicates useful information! Why would you hide that?
I find this a problem with all the newfangled webpage designs... but on others, there's an indicator that there is more content below.