Currently, Applications can't be defined globally.

Imagine the situation that you are defining different Templates, for example
for backup, for web-applications, and and and... each template defines an
Item for a "process-check", one Item for a service-state and so on...

Wouldn't it be fine to see then the process-check under Application "Processes"
and the service-state under "Services"?

Forum discussion: http://www.zabbix.com/forum/showthread.php?t=17594
http://www.zabbix.com/forum/showthread.php?t=25377