One of the things that was so unique about the band was the fact that they were all great musicians. Most great rock bands had at least one dodgy member; not LZ. Rock solid, all four of them. This will surely make choice of the stand-in for John Bonham absolutely critical if the kind of Phil Collins/Live Aid debacle is to be avoided (Zack Starkey, perhaps?). Like Athanasius and the Cappodocians, the whole is greater than the sum of the parts.
The ticket prices will, presumably, be preclusive -- ironic, as always, that a musical form originally designed to thumb its nose at the establishment has become so internalised within the new establishment and more costly than opera. The Zeppelin reuinion will, by and large, be the preserve of the very rich. A bit like the blues becoming the quintessential white guy's music. But I bet the raw power of Plant's vocals and the lyrics of songs such as `Since I've been loving you' probably speak with more honesty and clarity of the reality of the human predicament than either the bland pop of the Spice Girls redivivus or much of what passes for Christian music in the contemporary scene.