does anybody use uddi anymore? Or is it's functionality now encompasses by WCF? Does Azure change anything regarding to the usefulness of UDDI? Can you please give me a practical example when UDDI was used?
UDDI is dead, the idea behind UDDI was to discover web services and their capabilities in some sort of web services marketplace. IBM, Microsoft, and I think WebMethods operated public UDDI servers, but those were shutdown a few years ago probably due to lack of interest.
In the real word it seems that you can just put your WSDL description of a web service on the same server that is hosting the web service. Also many frameworks will generate the WSDL for you from your code and existing xsd files using the principle of convention over configuration, see spring web services for an example.