[Monochron]

I think asking yourself two questions will solve this for you.

Q's:

1. What programming skills do your students or mentors already have.
2. What are you priorities for the team going to be?

A's:

1. If you have students or mentors who are familiar or proficient in one of the languages I recommend going with that language (unless it interferes with question 2). If you do not have any students or mentors with experience, then I would recommend LabView (unless it interferes with question 2). The breadth of support and slightly easier learning curve of LabView make it a great starting point to quickly build a successful robot. Also, LabView is used often in industry, especially in robotics. While your students won't really be familiar with a written language, knowing LabView is still a valuable skill.
2. If your top priority is building strong computer scientists then one of the written languages will likely give them a broader set of skills (imo). The concepts learned in C++ or Java are applicable to many sets of written programming languages. If your top priority is building a competetive team quickly then LabView may be better due to it's somewhat easier learning curve and the breadth of support that you can find. If your top priority is building the most sophisticated robot you possibly can then I think one of the written languages is going to be more useful (check and see what other top teams are using).