idea: make update-manager warn user if application updates are available for app being run?

Binary package hint: update-manager

Idea for discussion: would it be possible to have update-manager warn the user if:

- updates are available for the application the users is running/about to run.
  (would require "apt-get update" or equivalent to auto-run daily?)
- updates have already been downloaded (but not yet installed) for the application the users is running/about to run.

The idea here being that maybe we should warn users if "security-critical" apps like firefox have available updates which have not yet been applied.

This idea may need careful consideration as some users may construe these warnings as nagging. As such, maybe a subset of applications could be considered. That subset might have to be graphical though unless we got clever with LD_PRELOAD to warn console users (although there are obvious problems with that).