No MSN messenger. There are great alternatives however, and if you wish to Webcam I'd suggest using AMSN. You can get it through Synaptic. Compiz-fusion is installed by default in Mint. To help you figure out how to get it working it depends on the graphics card, if you have integrated graphics it should work out-of-the-box. If you have dedicated NVIDIA or ATI cards, then you have to get the proprietary drivers for it.
1. If you have intergrated graphics go to step 2 if not go to step 3.
2. Go to mintmenu, preferences, appearances, go to the Visual Effects tab, and try normal or extra. For more customization go to Synaptic Package Manager and install compizconfig-settings-manager.
3.If you need the proprietary drivers i'd suggest a program called Envy, you can download the latest version here
http://www.albertomilone.com/nvidia_scripts1.html. Use the program and automatically install the drivers for your system, once you have that all done, go to step 2.
PS: You're in the Newbie section, we know you're new and have questions.

. Try and focus your title more towards your problem, the more specific you are the greater chance someone reads your thread and can help if they know about it.
Cheers.