At the moment, until we get our hands on all the tools, it is impossible to know quite what will and will not be possible. From what I've seen myself so far, my main concern is the lack of fine control over verts. In APCD, a lot of 3D work is created from terrain. This looks impossible in Unity, and I imagine everything is going to have to be constructed and then imported from other programs. This is not necessarily a bad thing, just more to learn.
It is obviously possible to create fantastic terrain to use in Unity, I'm just not so sure that it can be easily done from within the Unity program itself. Everything that PP have shown so far (apart from the hole creation demo) seems to have been created using imported data.
Mike mentions 5 minutes of work to get to the Course Forge stuff, but that is by importing an APCD mesh that has taken many, many hours to create. Creating a terrain from scratch is going to take considerably longer. Using Bing map data is going to leave an awful lot of work to be done, too, with just a few brushes. The example of creating a par 3 hole in 10 minutes was inspiring, but designing a complete course this way, without first pre-planning the terrain could lead to a lot of design issues for some.
I think the Course Forge is very exciting, especially for new designers. They will be able to select what they want from existing libraries, and produce a nice looking course pretty quickly. I just hope that there is still scope for the more intricate work required by the more seasoned designers too.