Via IGN

The Nihon Keizai Shimbun reports today that Nintendo has upped its April shipping estimates for DS Lite. The company had originally expected to ship 700,000 units throughout Japan during the month, but has now updated this figure to 800,000.

Being that it's now May, we're not sure why Nintendo is unable to give a specific number. But, seeing as how the system continues to sell over 150,000 units a week and is still hard to find at retail, we're inclined to believe this report.
With increased DS Lite supplies in Japan, a US release for the slimline model shouldn't be far off. Expect to hear details on the system's US release at E3.