I see Lynn Allen has written a post explaining how to restore the “classic” interface. I commend Lynn for doing this in response to the requests she’s been receiving. It must be pretty painful for some people at Autodesk to see their Technical Evangelist showing people how to turn off AutoCAD 2009’s Big New Feature, but it’s absolutely the right thing for her to do.
The worst thing Autodesk can do right now is go into denial mode, which has happened more than once in the past when users have reacted negatively to various things. This post from Lynn gives me hope that maybe we don’t have to go through that stage this time.
Anyway, if you want more detail about putting things back to normal, have a look at my earlier post on the subject. I’ll add one more tip here that you might otherwise miss: if you want the old layer interface to be invoked by the Layer command rather than the new pallette, set the undocumented system variable LAYERDLGMODE to 0.