A Macbook is precisely what you need. The Mac ships with 2 DVDs - the Mac OS X Install DVD and the Applications Install DVD. The latter is for GarageBand loops, which unless you happen to be a musician is useless to you. The former, however, is more interesting. It contains the installer for something called Xcode - the official development environnement for Mac OS X. It is very powerful as an IDE, and with it comes what you likely most want - GCC (GNU Compiler Collection) and Java (javac).
The version numbers are 4.0.1 and 4.2.1 for GCC (Good enough - I built my own GCCs, 4.4.3 and 4.5.0 from svn revision control and releases) and 1.6.0_17 for Java, which is to say the latest. The GCC bundled with Xcode is tuned to Apple's whims and is more focused on Obj-C than on other languages, with the result that it is slightly incompatible with the GNU's version of GCC. However, that same GCC can be used to compile Assembler to binary code. I have nothing bad to say of Java on Mac OS X - if anything it is a touch better than elsewhere. You merely have to keep updated with the latest Java Updates # for Mac OS X and you're safe. Netbeans exists for Mac OS X, and it is easy to download and install.
To be honest, as I hate the presentation of Xcode (It was made for Obj-C GUI programming more than anything else), I use the variety of text editors for Mac lying around. My favorite is a very cute application called Smultron - very user-friendly. Takes down Xcode's unfriendliness single-handedly.
Visual Studio doesn't exist for Mac, but there is a way around this - Boot Camp.
Symbian can be booted alongside Mac OS X.
As for Boot Camp: It allows dual booting of Mac alongside Windows, so if you wish to install Windows it is an easy matter of reading the Boot Camp instructions and following them. Windows will then run at native speed, so there are no worries there. You will be able to install everything that you wish on your Windows partition and everything will run precisely as a Windows would run, like Visual Studio C++. Notice, however, that Boot Camp was only designed to boot Windows: Going into triple- or quadruple-boot is generally no-man's-land in computing and needs to be done VERY carefully. For this reason, if you do wish to boot Mac, Windows, Linux (Ill guess Ubuntu) and Symbian OS, I recommend you buy a 500GB hard drive, partition it 5- or 6-way (A spare partition is always useful, believe me) as soon as you get your Mac, then proceed to install all OS-es you need.
VMs are not recommended by me - they are awfully slow, though if you need rapid switching you're welcome to use them.
You might run in a few bumps in the road to Mac OS X. Some cons are that Mac uses its own filesystem format, called HFS+. Linux understands it but Windows does not unless through free third-party drivers, which if I am not mistaken are included in Boot Camp. Windows also uses a new filesystem called NTFS, which Mac does not understand (the feeling is mutual), unless you use the free NTFS-3G driver from Tuxera. The layout of Mac OS X is roughly identical to Unices, but has a few (not a lot) different tweaks. For reference, the GUI Terminal is found at /Applications/Utilities/Terminal.app. Suffice to say you won't encounter much problems.
Pros include utilites you won't find in Linux, such as my favorite, open. If you type open "name-of-file" it will open it in whichever GUI app it usually opens in, which makes you think "why didn't somebody think of that earlier?". Or for example the command say. Type say "This is cool" in the Terminal with speakers on and listen carefully. Look around on Internet for more of these hidden gems which make Mac so great an OS.
Finally, I would like to conclude that Mac OS X is an excellent platform. I will confess my hate of Linux here, but Mac OS X makes up for it. It is very Unix-like, but is idiot-proof and manages to conceal Terminal work (because the command prompt is so named in Mac OS X) from the mere mortals in a way no Linux distro will ever manage.