Hello, I am a programmer for Team 900. We are one of the beta Teams for the 2015 control system. My team uses Labview, and we have found that the language works the best. Most of the errors on the beta forums seem to be about C and Java. We have found that labview is powerful, has the most community support, and is extremly easy to teach to new students, although from your post it seems that many of your students have a background in Java. Our team used Java during my freshman year, and we had many difficulties. Labview is easier to debug and spot errors, expecially because you don't have to worry as much about syntax. Java is also not particularly optimized for the realtime enviornment of the RoboRIO. If you can, I would highly suggest switching to labview. C has less problems than Java, and can be useful for some lower-level stuff, but still has the same problem of being difficult to teach to new students. I wouldn't recommend programming in anything other than the above three languages, because after that support from both the community and from FRC is extremly low.
If you have any questions about the new hardware, feel free to contact us at the email
programmers@team900.org. We are right next door to you in Durham, NC, and gave a presentation about the hardware at THOR. We will also be giving a presentation at Chapel Hill High School in December.
Edit: Something that I have overheard other teams saying multiple times is that they don't want to use a "Kiddy" graphical language, equating labview to something like scratch. Labview is a powerful industry tool designed for control systems, and that is what a robot is: a control system. One of our mentors works for Cree (LED Light Bulbs) and labview is used in their systems.