I used Google to establish that there is not already a post from 2015 that mentions "roadmap" in the subject line. Such would be a good skeleton for anyone new to the list (like me).
1. Increase the 7 Tx per second - by increasing block size.
2. Do something about the trend toward centralization. This is really two issues in my mind:
A) Mining is falling to an ever shrinking number of businesses with the infrastructure to run a datacenter.
B) The protocol as it is will soon make common computing machines inadequate for running full nodes, and as a result they will not be able to contribute to the ecosystem in meaningful ways.
Feel free to copy and then remove or alter any of that.