Buying a MacBook [ for a programmer ]

I am planning to buy a new laptop, mostly I will use it for programming and stuff connected with studying computer science. My current target is MacBook Pro. I know that I will have to write code in C# occasionally so I will have to install Windows or run it on virtual machine, but I don't plan to develop in .NET in the future.
What other languages I will need :
- python ( in a big extent )
- java
- c/c++
- javascript
Is there someone who already develops apps using languages mentioned above?
I know that java is fully portable, there is also no problem with C and C++ ( except that I wouldn't be able to code in visual C++ studio ). With javascript there also will be no problems. However I wonder if Mac is a good choice when we take script languages like let's say python, ruby under consideration. Sometimes u want to use/install various versions of python and install various additional libraries or use external frameworks ( like Django, Pylons, Plone ). Also u want to use tools like virtualenv and etc. Will Mac handle it all?

Every programmer I know who works in Python or Ruby works on a Mac.

I develop in Python and I've encountered only one issue: Apple ships Python as a 32 and 64bit binary and enables the 64bit version if that works with your machine. This can cause a problem with some modules - wx doesn't like 64bit Python for instance. This is easily changed however - either simply set the 32bit version to be the default or download a 32bit Python build from their website.

Although OS X comes with Ruby, Perl and Python, you'll end up updating them manually if you want to keep up to date. Apple is a few bugfix releases behind. Also of note is Apple's version choice: they ship with Python 2, not version 3. I like that since the modules I need only work in v2 (like wx) but if you need v3, it's a simple download away.

Also of note: Mono works with OS X. As long as you're not using something like WinForms or any other Windows specific framework, it may work for you.