Let's see... this is what i would do:
1.- Backup your Database with the File*Library*Backup LIbrary feature.
2.- Backup the whole "Data" directory inside the current installation of MC. This is where Cover Arts is stored in the case you're not storing it inside the files. (Actually i would copy all the Media Center sub-directories). Bear in mind that you should keep same path names for new MC install directory, and that holds true for file location on your new drives.
3.- Copy/Move your songs to the new drive. (remember to use the same paths as the old drive). If you wont'' be using the same drive on your new PC then don't bother with this, but if you aren't it'll depend on which OS you're using to change the drive's name (i.e from d: to e:, etc) if necessary.
4.- Install MC on the new PC.
5.- Copy your backed up "Data" directory inside the new Media Center directory.
6.- Restore your Database with the File*Library*Restore LIbrary.
7.- Uninstall MC from your old PC
If you have plugins installed then you should install them again on your new turbo charged machine.
Well, that's as far as i can do for you, my friend. If someone sees i've missed something then feel free to object and add.
Peace