Just incase you were not paying attention, DS firmware upgrade is in the works. Loopy is working on a hack that will allow booting from GBA cart without a passme. This will still require some means to exicute code (either a Passme or wifi method) as well as a temporary and simple hardware modification. Great work!
You can read progress in the gbadev.com forum.


Thanks to http://www.thepernproject.com/ for the news.