In JDeveloper technical preview 2 there is a sneak preview where you can export data of a rich table to excel.
In the next versions of jdeveloper there will be more possible , somehow Oracle made a interface from adf to .net framework. the jars and dll's are already shipped in technical preview 2 ( see the directory adfdi of the jdeveloper root) .
Now a small example of exporting table data to excel
First we have a rich table on a table emp where I put a button commandbutton with the text export to excel see below

now we open the component palette and go to the operations accordion and drag the export collection action listener on the command button.I only have to fill in a few parameters , the first exportedId is the id of the rich table then we select excelHTML . We are finished
We can now run the webapp and we can change the colums and the sorting of the table. The same data and presentation is copied to excel