While ESRI makes some great software, the price tag is not practical for individual use. I didn't bother learning anything else until I no longer had access to Arc, but fortunately QGIS makes the transition extremely easy. Most QGIS installations also come with a program called GrassGIS which operates in a different way but has some additional features.
I definitely think it is wise to attend the free conference, learn everything you can, and network. Even if you stop using Arc once you are finished with school, the concepts that you learn will be broadly applicable. I am with you that open-source is best way forward, but understanding how to work with the industry standard remains a critical tool. Nice post!
RE: Should I Pay or Should I Go? Discussion on GIS Software