No the interface is very different between Terragen 2 and Terragen 0.9.43.
Terragen 0.9.43 is probably easier to learn and your right, there are many more tutorials available for Terragen 0.9.43.
The main differences between Terragen 2 and Terragen 0.9.43 are as follows:
Terragen 2 can render complete worlds, many of them in fact. It can also render height fields.
Terragen 0.9.43 can only render height fields (up to 4096 x 4096 I think)
Terragen 2 can import other objects and render them within the Terragen 2 world you create.
Terragen 2 can render true volumetric clouds
Terragen 2 uses a nodal interface
There are more tutorials and plug-ins available for Terragen 0.9.43. (Hopefully there will be more tutorials for Terragen 2 soon)
In short Terragen 2 can do everything that Terragen 0.9.43 can do and a whole lot more.
Download the Terragen 2 demo and take a look at the tutorials
here.
Have fun
Richard