I’d like to see this in the next revision of the Unity terrain engine. 
(I’m talking about the shadows/prettiness, not the regeneration.)
I’d like to see blob shadows working with the next version of the Unity terrain engine 
You just aim too low. 
Those videos were pretty awesome. I’d love to see something cool like that done in Unity, though I don’t think it ought to be built in.
The tree regeneration, that’s probably left to us non-UT people, while more important things get added. The sweet real-time shadows would certainly be nice, though.
(not that I could use them until I can afford Unity Pro…)
No, you’re misinterpreting me. If the next version supports self-shadowing grass, the next version won’t be coming out until 2009 or 2010, and meanwhile I won’t have blob shadows.
Ah. 
That makes perfect sense actually.
I love the shadows on the vegetation and tree trunks, but I wouldn’t be that bothered if I never saw tree regeneration in Unity
Boxy
Well, you can create it yourself
But as a feature for the terrain engine in Unity, it makes no sense. I think more than anything the terrain engine needs more extensibility and open API, so that all these things people want can be had, without having to cram them in Unity which makes no sense.
I can’t see any reason why awesome shadows should not be built directly into Unity, everywhere. That doesn’t bloat Unity. It makes it more cohesive.
Just making an option for the terrain to cast and receive shadows makes sense I think.
But “awesome shadows” are something the artist and game designer create together, the engine never does it by itself. And for “awesome” real time shadows, you probably need to require specific hardware, limit how people can build scenes or implement multiple shadowing methods.