Nope, from what I've seen, it's impossible. People have tried it... Xlink tried really hard to get it to work, but the wireless configurations in the DS, quite frankly, suck...
No, believe me they've tried. The Wireless LAN play for the DS is extremely complicated compared to that of the PSP. Nintendo decided to use some stupid protocols, presumably to keep tunneling away... there have been many attempts by the big guns such as XBC and Xlink but no results.
