Actually i just read on Guru. Regina posted this:

"The re-design of the Underworld was intended as a way to add fun new content to the game while preventing ridiculously fast speed clears up the Underworld. (For example, the first Shadow Form group to beat Dhuum took 85 minutes rather than the 7 minutes it used to take similar groups to clear UW.)

This was not an attempt to address all of the concerns about Shadow Form Assassins. That will happen in the next major skill update, which will include big changes to Shadow Form and may also include changes to other prominent farming skills.

Work on this next update is currently in progress, but it looks like it will not happen this month. We are aiming for not only “tweaking numbers” of certain skills, we are looking into making changes that will require extensive testing and implementation time. We intend to heavily involve the Test Krewe in testing and evaluating the changes before they go live. Unfortunately it took longer than expected to get the Test Krewe off the ground.

I hope this sheds a little bit of light on what’s happening and where we are going."

source
http://www.guildwarsguru.com/forum/s...php?t=10413458