The main NetBeans 6.5 feature I have been looking forward to is the new database support. For details about what is coming, look here for details.
For now, we already can use code completion, some features as editable queries result, quick column info on result table and another really cool features. Another interestig feature is the SQL History. You can see below an image about what is coming...
BTW, the execution plan will be implemented just for feature versions. If it is important to you, vote for it now here!