Turbine announced that they will be bringing down the DDO Game servers for a hotfix on Thursday:

The DDO Game Servers will be brought down on Thursday, May 1st from 7am - 10am Eastern (-5 GMT) for a hotfix.

This hotfix should address the severe lag issues and some monster misbehavior caused by lag, that has been experienced by players this week.

Turbine would like to thank everyone for their patience! See you in the game soon.

I hadn't seen severe lag, so maybe I've been lucky. Still, fixing it is better!