Well, StackOverflow is a huge comunity and I have found it very useful over the years, especially when having a certain urgency to get my problem resolved. Any time of the year and even in the middle of night, it is rather easy to get a reply. On overall I like SO but I must agree that it is better, at least for now, that B4A stays here at the forum. Of course, SO is a great way to get B4A better known but at the end of the day, I think users will eventually find B4A when searching for something they don't understand in Java/Eclipse and realize it can be done easily in B4A (in an easy dialect of VB). In this way, the B4A-comunity will grow further.
Very often I get the impression, not only at SO, that people think B4A is a toy-language. If they only knew.......
If one uses SO, one should definitely only use the Basic4Android-flag. Not only for the reasons mentioned by Steve above but also to avoid that helful and friendly SO-users "looses precious time" by giving legitimate replies in Java just because the Android-flag was included or B4A was not mentioned at all. See my post here:
http://www.b4x.com/forum/69607-post3.html
I am surprised. I would have thought that SO would be the ideal place for a person like you Agraham i.e. I mean with all the knowledge you have, you would have been notorius on SO by now.
....although I prefer you being here.
Just my thoughts.