www.nubiles.net/webmasters
and
www.payserve.com
both have XML dumps.
and soon EVERYBODY who has the Nubiles Tube Script will be able to export their entire site into the XML format. It's in the beta right now.
If ANY sponsors want a free solution to create hosted FLVs and XML feeds from their movie hosted galleries hit me up as my tube script can be used as the backend CMS to accomplish this for FREE!
As far as additional sponsors who have XML right now, anybody who is listed in the STXT admin as having FLVs has an XML URL somewhere. Too bad smart sponsors does not have an output anywhere with XML urls. I don't have STXT so I can't give you a list, maybe somebody would share.