I have now included my plugins for SketchUp on my website. I refer to my plugins as Instant Scripts -- Instant roof, Instant Wall, Instant Road & Instant Site Grader. A couple more are still in development and will be added soon. While I really enjoyed my cadmonkey days using Autocad and writing lisps on the fly, I have much more fun modeling and writing scripts in SketchUp.
But there is still a place in architecture for 2d. We are 2-dimensional creatures. We move about in a horizontal plane, then relocate to another plane via a stair or elevator. And builders continue to layout buildings in 2d. So for architectural tools, my vote is: SketchUp plus 2d cad.
On the SketchUp Scripts page you will find several plugins. Read - Instant Roof Plugin reviewed by Google (Nov. 2010). For each script there is both a free and a pro version. Please download the free versions and give them a try(sorry no free version of Instant Wall). Plugins are for SketchUp and SketchUp Pro 6, 7 & 8, Mac or PC. I hope you will find them useful.