A recent issue of Nintendo Power magazine says that the previously-announced Opera web browser is headed for the DS in June.
Opera's Berit Hanson, in an interview with Cubed3.com, says the browser will support both a fit-to-width mode that reflows the page to fit the DS's low-pixel width, as well as a DS-specific mode that uses the upper screen to magnify portions of the full page, which is shown in thumbnail style on the lower screen.
No date has yet been set for a release outside Japan for the Opera software.