The GNU Radio conference (GRCon15) is a yearly conference discussing all matters related to GNU Radio, an open source graphical block based DSP programming application that is compatible with most SDRs, including the RTL-SDR. Many of the presentation slides are now available for viewing on their website.
There are many interesting presenations like how to start building an SDR from scratch, getting startet with tools like GNU Radio, Pybombs etc., but also more important topics of the near future e.g. how to get GNURadio into undergraduate schedules or how to implement SDR platforms into mobile computing platforms.
IMHO to the last topic: I can predict NOW, that in some 2-3 years it will get very popular to use the embedded FPGAs in desktop CPUs to realize state of the art SDR platforms for TRX. And the next step (maybe 5 years) this will move to the mobile world and we can download the newest basebands when going abroad. But also new ways of communication could be possible with this. communication under the radar e.g. that you use your own proprietary protocol in your family or sth. like this.