Absolutely you can start using it. I evolve it every single day. I use Protopub exclusively as my feed reader, and have been for about a month.

Right now, Protopub is an experiment, but it also serves as a beacon to other likeminded hackers in NYC, where I live, that I am interested in meeting others who want to create unique and technically savvy projects. It has done a good job of doing exactly that so far.