According to this press release, Oversee.net (which also owns DomainSponsor.com), has purchases a privately held portfolio of 35,000 names and is planning to purchase additional portfolios.

Oversee.net monetizes more than one million domain names and has more than 100 million unique visitors per month. [...] Because DomainSponsor has a close relationship with the domainer community, Oversee has a unique ability to quickly execute potential acquisitions.