At this point you don't need to become an expert in any particular language or paradigm. You should learn about as many different things as you can. It's fine to be a Java programmer or a C# programmer, but you're much more versatile if you're a programmer/engineer that is willing and able to learn whatever tools are necessary for a project.
Learn one of: (Object-Oriented procedural)
C#
Java
Objective-C
C++ (one of the others would be preferred)
Learn one of: (Procedural)
C
Fortran
ASM (This is lower level, perhaps pick a RISC ISA like MIPS)
Learn one of: (high-level scripting)
perl
ruby
python
Learn one of: (Functional)
Lisp
Haskell
Erlang
Learn a few of: (Grab-bag)
SQL
Lexx/Yac
JavaScript
shell (pick one)
Verilog or VHDL
Prolog
There's thousands of others to choose from, as well
If you've at least tasted something from every paradigm and "get it" to some extent, when you need to step in to a new situation and use a new tool you won't be starting from scratch. The syntax of a language is far less important than understanding how things are expressed in different models. Once you understand what a class is and how it behaves, it's pretty easy to find the syntax for declaring one in any OO language and implement it. If you don't know what an Object is or why you might want to use it, you're going to have a much more difficult time.
Individual language syntax is not worth being an expert on. What does come in handy for many newer languages is being very familiar with their libraries/frameworks/etc. I'm thinking specifically of Java and C#, with libraries that can easily overwhelm. It is worth familiarizing yourself with one or both of these, but it's probably even better to learn how to really read documentation.
Something that surprises me on this board is how often things are spelled out in documentation (perhaps not clearly) that people don't get. You need to learn to think like a programmer (and perhaps a bit like a technical writer) and become adept at seeking out, reading, and absorbing API documentation, language syntax documentation, code samples, etc. If you have these skills, even if you are tossed into a situation that requires a lot of interaction with an API you are unfamiliar with, you'll be able to spend some time reading and at least be able to get started.
Since you have access to (hopefully) some very smart people in your professors, you might ask them what their pet/favorite language or paradigm for programming is. If you start learning about that, then you have someone to talk to about it, and you might have a chance to establish a relationship with them which can come in handy for all sorts of things (references, getting you in to a closed section of one of their courses, someone smart to bounce ideas off of, etc.).
Good luck!
-Lee
