I think Nintendo's gonna take their time in building firmware 1.5 because well... Most flashcards load up as Danny Phantom, so I don't think Nintendo will be able to differentiate between flashcards and the original Danny Phantom game. And besides, the DSi XL is out in the USA on March 28 if I heard correctly which is pretty soon. I doubt Nintendo will make an update by then.
yes the DSi XL works perfectly with Acekard AKAIO 1.5 firmware unofficial ............there is a link on this site to the nds file you need to run, to reformat your flash card using your old dslite first..........a.k.a dannyfantom hack.
i use one with a 16Gb card with the games split into 3 sections so that the folder sizes are kept below 8Gb which cause errors if not.
I just need to learn now how to play movies on it.