In an OpsMgr 2007 deployment, I was getting Critical Errors for a SQL job that wasnt finishing, and my client wanted these alerts to be Warnings instead of Critical.
In MOM 2005, in order to override the severity of a rule, you had to copy the rule, change the severity on the new rule, and then disable the old rule.
In OpsMgr 2007, the process is all handled with overrides in one step. See the blog entry below, which Cameron Fuller pointed out to me
Here is a summary of the values available to a severity override:
Alert Severity – Its corresponding integer value
Critical – 2
Warning – 1
Information – 0
Alert Priority – Its corresponding integer value
High – 2
Medium – 1
Low – 0