Rich,
First off, 4.0.1 is out now.. should fix the social button issues from your other post, but if not, let us know.
As for the Twitter idea, I've added it to our investigation list, and agree it'd be a nice improvement. With our LinkedIn extension coming out next month, we're currently re-evaluating how we're doing the social integration in a way to make sure it's compatible with different social extensions we have (or will develop). The idea is to have 'basic' social functionality in all the extensions (or shared between them), but if you want more robust integration, similar to what we have in JFBConnect, you'd need the 'full' package. The Twitter follow button would be a basic thing I can see adding, it's just a matter now of figure out the easiest and least confusing to make everything work well together.. but that's our job
Hope the explanation helps a little, and definitely appreciate the suggestion!
Thanks,
Alex