In my podcast about Citrix iForum 2005, one of the trends at the show I noticed was that there were a lot of vendors focusing on monitoring end-to-end applications instead of just monitoring metrics on servers. The idea is that you really don't care about whether Server X or Server Y is running--what you care about is that your application is working.
The definition of "application" can vary greatly. In many cases, an "application" delivered by Citrix requires that your Citrix server is available, as well as your IMA data store, your Citrix license server, and your Microsoft TS license server. It also needs a domain controller to authenticate users and most likely a file server for roaming profiles or home drives. The application itself might require a backend database or a web server.
In terms of availability of the "application," all of these components must be in place and operational.
Current versions of Microsoft Operations Manager (MOM) focus on the availability of servers. If you want to monitor an application, you would have to watch metrics for several servers at once. The new version of MOM--version 3--will allow you to define applications that you manage and then specify what needs to be running on what servers in order for an application to be available.
I think this is a great change to the way MOM functions, and it will give many of the application management vendors at iForum a run for their money. (Remember that Citrix has a MOM Management Pack available for Presentation Server today.)
MOM v3 isn't scheduled to be released until late 2006, so there is still some time for all this to get sorted out...