I see that BI Publisher supports Excel 2007 as an output type because I can select Excel2007 from the BIP web interface when I try to generate a report. However, when I want to run the report by calling BIP from a web service client, there isn't an available option to specify Excel2007.
The document outlines the available format:
The output format of the requested report. Valid values are: pdf, rtf, html, excel, excel2000, mhtml, csv, data, flash, and powerpoint.
I want to use the Excel 2007 format to avoid the issue described here: