I'm not exactly sure I understand what you mean by the phrase "security certification for applications," but my answer to the more general form of the question without the phrase "for applications" is as follows: IT security certification remains one of the hottest and fastest growing areas in the field and is likely to experience strong demand and growth for the foreseeable future. If the intent of your question is to help you decide whether or not you should pursue such a certification, given that you have an IT background and the ability to learn and master the material related to information security, pursuing such credentials is probably one of the best career moves you can make.
For more information on this topic, visit these other SearchSecurity.com resources:
Ask the Experts: The benefits of security certification
News & Analysis: Climate elevates importance of security certifications
IT Career Expert: Achieving career success in challenging times
This was first published in October 2002