Mark Drew just announced an earlier version of the ColdFusion 8 dictionary for CFEclipse. Grab it now.
One thing that may not be obvious - or maybe you didn't know about CFEclipse, but Mark has set it up so you can set the version of ColdFusion you are running. That way if you are using ColdFusion 6, or Blue Dragon, or Railo, and use a function that only exists in ColdFusion 7, you will get immediate feedback of the problem. This is per project - so if you work in various versions of ColdFusion, you can set each project to the one being used.