Dave, you took the words out of my mouth! (or keyboard as the case might be) Here's what I wrote:
It means the glideslope component of the ILS is out of service, so the approach must be flown with only the localizer. This type of approach would more closely approximate a VOR approach, with the exception of the sensitivity of the localizer, which is 4 times more sensitive than a VOR.
Also, generally the decision height or minimum descent altitude is raised - without a glideslope indication, the approach will terminate higher above the ground, considering a localizer approach is not a precision approach, whereas an ILS is.
Here's a link to an explanation of an ILS:
http://en.wikipedia.org/wiki/Instrument_Landing_System