Oh, it'll continue to develop, all right; it's too good a technology for aerospace, F1 and all that not to have lots of money thrown at it, because it can produce all kinds of "impossible" things. Give it time, and Warco will be selling them…
As with all this kind of thing, you need to be able to create the object as a 3D CAD model first, and the rapid prototyping gubbins does the rest. Even then (see the way the propellor is located) you're often constrained by the way in which the model is created on the machine, so it's not simple even then.
Creation of complex 3D shapes on a computer is not simple. I know; I've been trying to do it professionally since 1995. When shapes get curvy (like motor cars, shoes, any kind of arty-farty sculpture), the digital definition of the shape of it becomes very tricky indeed. Modifying what you've created because it "isn't quite right" can be a nightmare – and as for trying to edit somebody else's creation – you'd often be better starting from scratch.
Luckily, most of "our" type of stuff was invented before about 1960, and is perforce usually defined fairly simply as far as 3D digital definition is concerned. Lots of simple flat shapes and relatively easy cylindrical bits more or less define a steam locomotive! Unless you want to re-create (say) a 1950 vintage motor car. Even then, if you have access to the real thing and a 3D laser scanner, you're laughing.
A New Zealand chap on another forum is building a 5"G BR standard 3MT, using 3D CAD to produce wax models of the castings, which are then cast in steel. It is looking absolutely superb – I think his cylinder casting includes some bosses which are not actually used for anything – but they appeared on the real one. And it's all hidden by the cleading afterwards…
The more technology improves, the more ways there are of making "models" or whatever it is you wish to call them. Some people embrace it, and create magnificent things of beauty which would be next to impossible to create using a treadle lathe and carbon-steel tools. Each to his own.