Current Situation: For the account whose wall you want to keep track with, you don't get notified if there is any new mesage posted.
Suggestion:
1. you get notified in BTS client when there are new messages on the wall of the accounts you want/choose to track (address book could be a good start), those people could be your friends, business partners, or anyone you definitely would care.
2. A notification center would be great to keep those messages (trading, mail, wall, etc) recorded and found in one place.