What do you think is the likelihood that eventually there will be accessible means to discern your true identity from your online, anonymized one?

This question is extremely interesting to me for its implications for the future of (e-)privacy and internet communications. I realize that this it is already possible by way of court orders to force social media companies or forum hosts to produce your IP address, thus tracing to your ISP account, but what do you think is the likelihood that the internet will evolve in such a way as to allow for publicly-accessible sites or software that could easily reveal your true identity from your screen name on forums, blogs, Q&A sites like fluther, etc.? Not that I have anything to hide, but I think sometimes I get a little comfortable in knowing that my screen/username provides a certain degree of privacy.

Perhaps private investigators can already do this?

Is it inevitable? Is anyone else concerned by this?