REST and GeoRSS may be alpha-geek stuff and not quite yet ready for the masses, but, Ed, you're not helping when you frame them as lite technologies (emphasis mine):
It's not difficult to appreciate the problem, REST based interfaces, KML, GeoJSON, GeoRSS etc might actually be the best technologies to use today and would be the tools of choice of many, however like many other Government IT projects INSPIRE needs to follow the low risk route of SOAP, WSDL, WMS, WFS etc.
So we may find that organisations will use OGC style interfaces to communicate to other public sector organisations and the commission, while using lighter weight technologies to publish information to their citizens. This is no bad thing !!
HTTP REST is not about light weight (RFC 2616 is just as heavy as a WxS spec), it's about working with the grain of the Web.
The final paragraphs of Ed's (excellent, despite my one quibble) post hint at the biggest risk from using SOAP and WxS:
I am however disappointed by the continued focus on metadata driven catalogue services as the primary mechanism to find geospatial data, I don't believe this will work as nobody likes creating metadata, and catalogue services are unproved.
INSPIRE needs GeoSearch !!
Agreed. Service and data discovery is seriously hindered by the fact that SOAP and WxS services aren't of the WWW.