HTTPS is not always the answer, and Securesha.re is not meant to be a direct competitor to Mega. We are focused less on enabling the sharing of movies & applications and more on the sharing of sensitive documents, private information, and so on.
It's not best idea to share sensitive documents without using HTTPS.
A good read on the matter is Matasano's JavaScript Cryptography Considered Harmful: http://www.matasano.com/articles/javascript-cryptography/
Just curious, do you see any other red flags in the system?