The DSi XL has already been released in Japan and is known as the DSi LL. In the first week Nintendo had sold just over 100,000 units. This is an extremely low figure if you compare this to the previous DSi which sold a massive 170,000 copies on its first week.
Strangely it seems that the DSi XL has not significantly affected sales of the previous DSI in Japan, as the DSi has sold only slightly less than the DSi LL in the last week. It is odd that this has happened as we would have thought that new buyers would have gone for the latest model. Also, there must be plenty of existing DSi owners that are upgrading to the new model. This should have boosted sales even further.