I'd really like to be able to export the performance graphs in order to be able to use them in documents. They are a quick and easy way to get high-level information, suitable for quick proposals and the like.
The new aggregated (by site or company) performance tab allows you to perform .csv exports of the related performance tables.
Unfortunately, the actual graphs are not exportable - the only thing I can think of is screen-scraping it.
Why don't you click on the "online support" link at the top right corner of the web page and submit your request for enhancement. Please be as detailed as possible with your requirements in the ticket.