This now makes a LOT more sense. Thanks, everyone. And, many apologies for missing the introduction of extrusions as separate elements—for curves especially, since this is a lot more intuitive for solids. Nifty feature for very large projects, no doubt.
Both John and Mitch’s POV about defaults have merit. Defaults are tough choices for such a broad range of users and I don’t envy RMA on these decisions since, often, “no good deed goes unpunished”. 
No doubt the various “File > New Using Templates” were created to help address some of these issues (which are still only V4 files?). But, in truth, I have no idea of the differences between large and small templates. I had always assumed that the main and only difference was related to tolerances. However, I just checked this and it seems I’m wrong! While there may be other differences, the only one I actually noticed was the display precision being different? (How do users determine the differences between templates, other than the obvious units designation?)
As for the defaults question at hand, here’s a possibly crazy idea that might help address the large number of users/projects for Rhino – and yes, I predict this will be an increasingly large problem once MacRhino hits the shelves since the power of Rhino has the potential to scare the living daylights out of new users due to the (sometimes unavoidable) complexity.
I’ve often thought it would be great to choose an optional interview of sorts, where the desired template would be presented based on answers to a series of questions regarding (off the top of my head) things like: user experience level, tolerances, units, extrusions/surfaces, etc, etc. The power of such an approach could go far beyond defaults and settings, extending all the way to A) the interface that’s presented (such as what windows and tools are open or closed, B) a “click here” to learn more about this question, and C) possibly new features introduced and explained.
Good luck wrangling with this eternal challenge!
~Dave