I wonder if they will ever build this with an aluminium chassis. So that it's only major problem, a rusting chassis, will be a thing of the past..
Fitting an aluminium chassis on the current Defender would take it in the wrong direction, in my opinion.
An aluminium chassis would make the already-expensive Defender even more expensive, and difficult to repair outside of a specialist workshop. Aluminium would likely also spell the end for the simple bolt-together assembly, although this is of limited relevance to most modern-day users (but I love the idea that I can turn my 110 hardtop into a soft top in a few hours!).
The best approach would be to fit them with a galvanised chassis from the factory, which is already big business in the Defender aftermarket over here in the U.K.
Having said that, chassis rusting isn't as big of a problem as it is made out to be. The chassis is made from thick steel that takes decades to rust enough to be of concern and, by that point, bigger commercial users have long replaced their fleet with new vehicles, and smaller commercial users, second-hand buyers and, of course, enthusiasts have had them welded/stripped and coated/a galvanised chassis fitted. Besides, it's part of the ownership experience!
The Defenders
huge problem is just what everybody loves about it - it hasn't changed much in a world that has. A boxy shape that makes even the most economical diesel engines look bad, bolt-together assembly that pushes the driver to mental instability through obsessive rattle hunting, and such dated crash safety that means you still can't spec airbags, will spell the end for it shortly, unless Land Rover decide to dump a lot of money into it instead of the design of its replacement.
The next Defender will probably be of aluminium construction (with integrated body frame like the Disco), with a more-rounded shape to fit with the current range, much better crash safety, and a more refined/better designed cabin. One things for sure, the current models will become very expensive and sought-after.
Also: Who cares anyway. I'm not particularly concerned when I'm driving off road that my early 1990s 3.5L V8 isn't actually the one from the Benetton B194.
Anyone who says that they want to go faster in a Defender either has never driven/been driven in one above 50mph, or is incredibly brave (read: stupid). The current models will do 90mph... NOPENOPENOPE.