Pre 3.0 patch I had an addon, I believe was NatureEnemy Cast Bar that would show me when my target mob was casting and what it was they were casting. This bar came up right under their picture.  This is no longer working and now have to rely on DBM but it's not quite as accurate.  If that is what the addon was called; someone correct me if I'm wrong, is there an update that will work with the patch?

You are correct on the name, but I think I read some where that the original author of the Add-on wasnt going to up-date it anymore.  I may be wrong about that, but as of yet, I havnt saw an up-dated version.

NECB was great - miss it heaps! Best DoT and cast bar timer I found, and yeah that cast bar under the target frame was great.

EDIT: found out today NECB is being taken over by Softrix and will be updated for 3.0 patch - see wow.interface.com

There was a post on wowinterface that a rewrite of the addon was in effect. Hope it comes out soon

Look for Sorren Timers. NECB was taken over from Natur by other devs for the patch 2.4x cycle, but correctly you point out there is no 3.x version.

For the beta, I was using Ellipsis as a hot/dot/buff tracker.  It's no NECB but it wasn't too bad.  Polmonitor can perform NECB style tracking right on the actual spell button itself.