This question is a tough one for Dassault because it no longer markets Mirage 2000s. It has staked its future on the Rafale, and its sales efforts focus on that. This batch of Mirages can interfere with Rafale prospects.
Wiki shows that the current operators of Mirage 2000s are: France, India, UAE, Taiwan, and Greece. Egypt, Qatar, Peru, and Brazil each operates less than a squadron of Mirage 2000s. We can knock off India and Brazil off the list right away, as they both have a current fighter competition in which Rafale is a contender. Greece is having economic difficulties and cannot spend its EU bailout on surplus aircrafts. We can probably say the same [economic difficulties] about potential new prospects such as Argentina, who currently operate older Mirages. Qatar Air Force and Peruvian Air Force are too small to absorb any significant quantities.
Egypt and Pakistan are good prospects. However, Egypt has been buying F-16s, and is talking with Pakistan to jointly manufacture the Sino-Pakistani JF-17. A Mirage sale to Pakistan may also upset India, whose Air Force got Rafale back into MRCA.
So the remaining customer, however improbable, is emerging as the most likely prospect: Taiwan. Taiwan already operates 60 2005s, and wants to retire the last 33 of its F-5s. Dassault is unlikely to sell Rafales to Taiwan anytime soon. Taiwan is shopping for more F-16s from Lockheed, but Obama has not been warm to a sale. The stars are lining up for Taiwan, so to speak. It has the money, the will, and the capacity to pick up as many 2000s as it can get. A direct sale from UAE to Taiwan is unlikely to draw major diplomatic heat from China, due to UAE's status as a petroleum exporter. Another 60 2000s would address the growing cross-strait military imbalance nicely.
If Obama continues to drag feet on F-16 sales, Taiwan may end up a Mirage 2000 country. France still has 300+ 2000s it would like to replace with Rafales at some point. India has 51 2000s that were supposed to be placeholders for the MRCA, and it could unload those to Taiwan to help balance against China. As the F-16 line closes down, these surplus 2000s will be Taiwan's only choice.
PS: Edited for links and labels 1JUN2010.