I did some tests on dry film that is exposed with blue laser. You can find the result files under
http://tech.groups.yahoo.com/group/Homebrew_PCBs/files/BlueLaser_LDI_Volkan/ folder.
The minimum feature size that I achieved is 2.8/2.8 mil width and space. There is no problem to print 1.4/1.4 mil width and space but development of the dry film is a little bit problematic and it is not possible to do it with simple tray technique. The film that I'm using has a thickness of 1.5 mil, according to some google results the limit is 1.5∗film thickness, so if it is true it seems my results are almost at the limit.
Volkan