Of the things I miss the most when working with the Altiris suite the following two things are pretty close to the top of the list:
Customisable user message screens which may be associated per deployment task type. In other words, I don't want to have to create such type things to be part of my deployment package. A simple interface which allows me to communicate with my target audience with reference to what is about to happen on their device would be most useful. Connected to this is the lack of ability to have a countdown timer which may be associated with the task in question. For example, I deploy a certain job which requires the user to click on ok. The problem with this is that most users will just ignore this message, putting it into the background. What would be most useful is if I can set a timer on the job such that if the user has not clicked on ok within the set timeframe the job then automatically executes. This accompanied with a visible countdown box which appears on the screen has, in my experience, the desired effect to ensure that the user will execute the job sooner rather than later.