Right now when you go to one of your servers or clients you will see a graph with the average CPU and Memory usage.
It would be great to have additional graphs for disk and network related statistics.
The things I'm thinking of immediately is a graph to show me the history of diskspace. It would be great to see that 14 days ago i had 100GB in use and today i have 120GB in use. Other things could be maybe IO and reads/writes
And for network it would be great if I could see that 2 days ago interface XYZ was using 300mbps for 3 hours and then it dropped back down to 3.

Additionally i would be great if the graphs had an option to split it up into processes. I want to be able to see that process X has been using a lot of memory at night and drops back down during the day. Rather than just seeing a graph that shows overall memory usage because often that doesn't tell you a great deal of what is going on.