They go on and on about how "It'll be an austere wedding, William and Kate don't want it to appear grand..." That's why there's a £20m+ policing and security bill and all the Royal pomp and ceremony you can shake a stick at, then? Apparently the wedding is supposed to lift the national mood or some such nebulous drivel of that ilk.
It'll be like most other Royal occasions: the BBC and overseas media will love it, the rest of us will be either taking a day off to completely ignore said wedding or just go to work as usual anyway. It's not 1953, folks.