[acropolite (Phil)]

Cacheing allows much faster transfer than would otherwise be possible already.
I'd imagine that very only a very small proportion of the data transferred would actually travel from the originating point to the end user, the vast majority would come from cached sources.

As for the 25 Year lifespan, I couldn't find any confirmation using a quick google search, other than the blog that the original email was lifted from, sounds like an urban myth to me. I've worked with fibre for over 25 years I have never heard any mention of lifespan.

At the end of the day, uptake will be dependant on cost, if the cost is too high then uptake will be slow.

It's worth noting that Telstra's aim is to phase out copper completely your existing analog landline service will eventually become a VOIP add on to your broadband service whether you like it or not.

The fact that fibre is immune to moisture, corrosion and lightning are enough reasons to phase out copper. About the only thing that will damage fibre is rough handling, rabbits/rodents, and mechanical damage from excavators.

Fibre is so robust it will even withstand fire. When I worked for Telstra we had some vandalls set fire to a schoolbag in an enclosed area underneath where fibre was installed, the entire mechanical component of the fibre cable was melted and destroyed, the copper cable alongside failed as the insulation melted (that was the only way we knew there were network problems), the fibre however continued working despite around 10 metres of the sheath and buffer and loose tubes burning away, all that was left was the bare glass fibre still happily working.