1. The auto compile feature in Eclipse is great. Also how it provides quick fixes that actually work are just icing on the cake.

2. Visual manipulation of XSLs a la JDeveloper BPEL Designer is great as well.

3. Full compliance of the JEE 5 stack would be nice as well.

4. Maybe better Look and Feel would be another thing. It is always nice to have a pleasant looking work environment especially when one is coding in the same program for a long long time all day.

5. Make the Source menu more accessible by having it placed as a part of the right click menu for easier access.

6. More refactoring options a la Eclipse would be nice. I cant think of the specific ones I would like to have but I will try to look them up.

7. A smarter editor that is context aware would be nice...sort of like what IntelliJ's IDEA has.

Thats all I can think of at the moment. These are quick and dirty suggestions from me based on various features that I have used in other IDEs. As for something totally unique from the other IDEs it will take me a bit more time to figure those ones out.

Cheers!

It would be nice to have the following

a) Javadoc comment formatting like (or better than) the one available in eclipse
b) Formatting options for xml/html (The ability to specify the indentation width is very essential).
c) Code assistance and debugging support for Javascript.

Thanks

1. Case insensitive Import Assistance
When I am writing variables, I write them all lower case and then hit Ctrl+Space which changes them to correct camel case. It is faster because I don't have to use shift key or think about correct capitalization (don't get me wrong, I declare my variables with camel case). I constantly find myself hitting Alt+Enter three or four times in a row just to realize that I made mistake in one letter case (lower or upper)!

2. Merge Code Insight and Import Assistance
Why there are these actions separated? Can you merge Alt+Enter into Ctrl+Space. It is like that in Eclipse. To me it is much more convenient. When I am using some class I have to think did I already typed that class somewhere else in the file and press Alt+Enter or Ctrl+Enter consequently.
And Ctrl+Enter (Code Templates) should be merged too. To me it is much more natural to have all this Smart Coding features on the same shortcut.
There should be a switch in Options to choose between these two behaviors (separated and unified) (As in Eclipse)

3. Propose Java key words in Code Insight
Java language key words should be proposed when you press Ctrl+Space. instanceof, synchronized, implements, interface... are big words. (As in Eclipse)

4. Add tool tip with JavaDoc to Code Insight
When I am choosing method from list, I want to know right away what that extra boolean parameter (e.g.) stands for.

5. More JavaDoc
I know you can't distribute source code of your libraries (ADF). But you could distribute stub source files with empty method bodies and full JavaDoc comments. Maybe strictly speaking this is not a coding feature but it helps coding a lot. Currently, because of this, Ctrl+D (Quick JavaDoc) is pretty useless.

P.S.
Check out these on MetaLink:
4767168: Improve Consistency Of Smart Coding Features
4767166: Import Assistance Should Be Case Insensitive
4767176: Regrn: Focus Is Always On Code Insight Popup Even If Import Assist Is Invoked

This feature is as much for the code editor in SQL Developer as for JDeveloper, but since they share a lot of code, I'll post it here:

Can the code highlighting, and maybe even the visual designer for Java Server Pages be extended to work for PL/SQL Server Pages? It ALMOST works now, but at some points (I'll have to play with this a bit to give you specifics.) it breaks down. One thing I remember from when I tried to use JDeveloper to edit a PSP is that when I tried to reformat, it got confused when it saw PL/SQL syntax where it expected Java syntax, and did some very strange things that were hard to read and hard to undo.

This request would include JDeveloper recognizing that files with a ".psp" extension are server pages. I know that there are options to tell JDeveloper about extra file types, but is it SQL? No, Java? No. HTML? Not quite. JSP? Almost. Text? Well, yes, but if you say text, you get no code highlighting at all.

Formatting of Java code, similar to Ctrl+Shift+F in Eclipse.

Thanks Shay. JDeveloper 10.1.3 has the formatting of Java code with
right-click>Format file

Yes I was going to mention just that particular refactoring enhancement Charles, thank you. I will have to get the latest version of Netbeans 5.5 and Eclipse and make a clean list of what I like best of those IDEs and then post it here so that JDeveloper can potentially have those functionalities as well. Its the little things that count. I havent evaluated Intellij's IDEA yet but I here people claim it to be the best Java IDE ever. Everything from performance to a really smart context sensitive editor. But then again IDEA is not purely written in Java. It has a few DLLs and so on and I think that is where it gets its performance improvements from.