Only any good if it helps the whole organisation
Prince2 is a project management methodology not service management. Also some of the other acronyms relate to other forms of management methodology, not IT Service Management.
ITIL has only just gone to v3 and when I asked I was told that we can expect v3 to be the standard for at least a decade based on previous itteration.
Other than being picky about that sort of thing I tend to agree that certainly in smaller organisations you will just drown in your own red tape trying a full implementation of most of these book learnin' schemes
Even in larger organisations I wonder if a lot of the effort spent on implementing and running these inward looking control based methodologies would perhaps be better spent on giving the customer/end user what they actually want rather than producing a ton of stats to prove that what you have delivered meets your spec.