Features that are in MessengerDiscovery Live but arent in Plus!/scripts:
View contact MSN/Windows Live Messenger version
See the last message received and when (depends how you interpret this)
Imitate your contacts (using command !imitate) (one of the most sought after scripts if not the most. requires proxy usage but script devs are getting close and close to getting it 100% working
)
Be shown as 'using a mobile device'
Be shown as 'using web messenger'
Be shown as owning a webcam (these 3 being again proxy related)
Avoid being shown as idle (not too dificult. there MAY be a script already)
Nick name history (again depends how your interpret it)
Custom CVR
Messenger protocol debugging
Messenger server error logging