I considered getting one for a while and decided against. First of all I didn't think Id learn anything useful from it. (I just completed a Masters degree in Information Systems Security in 2008 which covered all the useful stuff).
Second, apart from in jobs advertised by less up to date hiring managers its not a technical certification, and is mainly a benefit for those doing the documentation style IT Security tasks (risk assessments, system security plans, compliance assessments etc). The GIAC certifications seem to be the hot IT Security technical certifications at the moment (GCIH, GCFA, etc).
Third, the CISSP test is 6 hours long, scheduled only at particular times of the year, and needs to be done on paper . The certification would need to be REALLY good for me to put up with that.