When I used BlueJ back in 2003 it was a total POS. I ended up doing all my assignments in Netbeans and just testing it once in BlueJ to make sure my TA could run my code.
When I dabble in Java I tend to stick with Netbeans though.
Has nice UI builder.
A WYSIWYG GUI editor in Java... never sure I've seen something so useless! D:
Yep Eclipse lovers can't never get over lack of UI editor ... we don't have it thus it doesn't matter.