The database isn’t entirely inclusive; more items are being added as they are discovered. Most of what is there right now is from leveling instances and quest rewards. It is nice to see that the purple gear we have pre-expansion appears to be stacking up fairly well.
I made some quick-and-dirty priest templates:
I’ll wait until a little closer to the WotLK release to do a more official stat weighing. The templates above should just be considered a general overview of what is out there.
If you are interested in the new expansion gear, be sure to periodically visit Lootrank to see the nifty things that get added!