just downloaded the latest msn messenger version and using it ,believe me although it have bright attractive graphics / layout but its heavy as hell ,beside that comparing the normal versions with this one i think for professionals and regular communicators its pain in A**
i personally like light versions for communications like Google talk ,although i have about more than 3GB of RAM but still when i use this messanger with 3d Studio max or any other heavy software i can easily feel the load on RAM