That's exactly why I'm so excited about those fractal possibilities and yet indeed also equally disappointed they first weren't in the Studio version.
Anyway, history now, it will be available

I think Terragen doesn't have "better" fractals than Vue. Yes Vue has more flavours, wish TG had those too, but in the end I think it runs down on how the software handles these procedural primitives and at the moment that's TG's key strength over Vue.
Matt found a clever way to organise the fractal data at rendertime to keep memory footprint low and stability very high.
You probably know that Vue is rather more like a pure ray tracer with different modes, in contrary to TG which does raytracing for shadows and such, but uses a system based no reyes architecture to deal with the complex geometry derived from fractal information.
I think that's where the key lies in their differences, strengths and weaknesses.
There's a heap of info on raytracing solutions for any kind of problem vs low volume of information on reyes architecture accelaration and rendering solutions.
I suppose the 3D industry is as prone to fashion as any other (like the medical research field where I work in).
I expect some stability issues. I remember starting with TGTP (TerraGen Technology Preview) which also had stability issues and sadly enough a couple of features enabled by default which slowed renders down 3 times to learn years later that it isn't required for stills at all (this is about the detail blending parameter).
I think TG got that label of being slow then and is still fighting against it which in turn connects to the paragraph above.
Anyway, stability, TGTP was unstabl'ish at first, but I remember it has improved drastically and quickly. If I recall correctly some have even mentioned it might be one of the most stable apps in CG out there.
I don't mind if TPF crashes every now and then at this stage, as long as it isn't every 15 minutes or so...
"Unfortunately" it's too good weather now to take a crack at it, so I'll let you know about my first thoughts later!