http://forums.lotro.com/showthread.php?t=316502A direct link to the defrag to download:
http://content.turbine.com/sites/turbine/support/turbine_datdefrag.zip (as I couldn't get the devs link to work in any browser I have installed).
Guys check out the above - I know I have gradually seen degradation in load times (especially as I copy my installs back and forward as back ups and overwrite my new install of lotro if I have had to reinstall windows for example).
So thought to give you all the heads up if you haven't seen it already

Enjoy, hope it can improve it for you all....
Be aware you will need to extract the files in to the same folder as your lotro folder (normally \codemasters\ the lord of the rings online\ ) - You cant run it just anywhere.
This is what you will see if, once you run it from the right location as above;

It might then be worth running windows defrag (or your prefered one) AFTER you run the tool. The tool defrags WITHIN the .dat files - but of course uses the file-system to shift thing about so will perhaps create some noncontiguous files/free space on your drive, and this is what windows degfrag for example can sort out.