With the coming out of 2.4, it probably means your old addons no longer work.  Well, for me, it allowed the opportunity to clean out my interface folder, and reload just my favorite adds. 

I redownloaded the latest 2.4 compatible versions of Cosmos and Omen, but some of my other favorite addons were not yet updated for 2.4, ie DBM.  Let me know what other addons you find useful.

USEFUL is the key word here.

thank you so much for the tips on addons. Because of patch 2.4 i lost my auctioneer/gatherer/enchantrix and cosmos had sum bugs even after patching. Should i just download the new cosmos for 2.4 and also are there newer versions for auc/gath/enchant? P.S. where can i find more info on Omen. Thanx

www.curse.com and www.wowace.com are the two i used for most of my addons