The developers at iStockPhoto have released an update to the plug-in for uploading images to iStockPhoto from within Aperture. The new version adds built in disambiguation, which is a part of the iStock uploading workflow.
To download the latest version click here.
And DigitalRailroad announced their Plugin for Aperture at http://www.digitalrailroad.net/corpsite/press_01-10-07.html
Best Regards,Eberhard