I wish that there would be a more concrete ETA available however with the drop of ICOs our options for funding have shortened and I do not want to promise unrealistic things.
With all this in mind, I can say that we are continuously trying to catch lightning in a bottle and create the best protocol that there is. This requires an incredible amount of effort and preparation and with limited options for funding, unfortunately this also means that a lot of time has to be spent and I would rather have the launch delayed if it means that at the end of the day everything works flawlessly.
Launching early is the capital sin of open blockchain projects.
I can assure you that everything is going really well. The protocol is getting more and more refined with each passing day. It is an iterative process that the more it is applied, the higher the quality of the product will be.
I am currently working on a new and improved version of the whitepaper which will describe everything in greater detail. We are also be constantly adding content to the wiki: https://github.com/purpleprotocol/wiki/wiki
Stay tuned.