DomainSpy maintains lists of the freshest upcoming and already expired domains around. It only harvests coms and nets under 15 characters in length at this time, so as to not oversaturate the lists with useless crap, and a quick WHOIS service is also available along with the lists for convenience.
We think it's a decent service, but we are of course looking to improve it with time by adding more domain sources. This is particularly so for the pending delete list, which is not very big. The already expired domains list is quite good already though.
http://www.adultgods.com/domainspy.php