I'm not at all familiar with the lego mindstorms stuff, so fill me in if you need to. There are two parts to what I want to say here.

1) If there's a gcc/g++ toolchain for the NXT bricks, then ros/eros can allow easy cross-compiling, management and deployment of your software (i.e. non ros programs and libraries) for the bricks. This in itself can be advantageous because alot of the awkwardness with cross-compiling and software management is hidden and lets you get on with teaching/working.

2) Cross-compiling ros itself and using ros communications and dependant stacks. That I suspect will probably be hard. Ros has some pretty steep dependencies in boost and log4cx. I had a look at the brickOS - it's using an ancient gcc (v2.95), which will probably mean alot of problems. I'm not sure about the new next bricks and whatever os they have running needs to have reasonably standard posix compliance to get those deps to build (even a minimal boost).

Can you quickly provide any details on the c libraries it uses, gcc version? How much horsepower do the bricks usually have compared with a smart phone?

Also, should consider the purpose of your course too. Does ros fit? Are you wanting to monitor across a connection back to a pc? (do you have ethernet back to a pc?). Are you scaling to the point where you feel like you want to modularise?

Regards,
Daniel