The mere fact that an intrusion detection system is the target of a potential exploit from this flaw is pretty worrying, given that an intrusion detection system is, well... an intrusion detection system. It is supposed to keep crackers out, and if it can be made to crash then it leaves the door open for further attacks from someone who knows what they are doing.
"The purpose of [an IDS] being there is to detect an attack. Being able to take it out could make way for a really nasty [subsequent] attack. If you were targeting a network, yes, this would be an important first step in keeping subsequent attacks undetected. That makes it of greater importance than a typical attack. Just because it's a security product doesn't mean it's immune to security vulnerabilities." - Michael Sutton, director of iDefense.