OK, the DS iPlayer is here and running. However, setup is a serious pain in the ***. Let Carni be your guide (read: relay all the help I got from GBAtemp and DSscene).
First of all, the GBA emulator only runs on the latest firmware. It's installing this firmware on the card that's actually hard, as the readme in the firmware download looks like it was run through babelfish. So here goes...
step 1) Format your SD card using the Panasonic SD formatter. This will optimize your sd's filing system and hopefully reduce lag. You'll have to Google it as apparantly this site thinks I suck too much to link you directly.
Step 2) Copy the "_system" folder and "update.dat" file to your SD card's root.
Step 3) PLEASE follow this step carefully or you could BRICK YOUR IPLAYER!!! Here's the fun part. Insert the sd into the iPlayer and power up your DS (you might wanna turn the sound off). The Majesco loading screens for "Fish Tycoon" will load and you'll be asked to enter your name. It doesn't matter what you enter, just touch continue and select a difficulty. Again this doesn't matter. Once you do, you'll get a Still White Screen. Put the DS down and leave it on the Still White Screen for at least two minutes (the update.dat file is actually updating the iPlayer's bootloader, at least I think that's what you call it on a flashcard. Just go do something else for a few minutes. Get a drink, smoke a cigarette, browse for roms, whatever...) Once at least two minutes have passed, turn the power on the DS OFF. PLEASE follow this step carefully or you could BRICK YOUR IPLAYER!!!
Step 4) Power your DS back up. If you've done this right, the iPlayer icon should have changed. Boot the iPlayer and it should ask if you want to update the system's OS. Click yes and it should update. TADAA! you've updated your iPlayer's firmware. This actually will allow the iPlayer to run on DSi firmware 1.4, now to add the GBA emulator.
Step 5) Open the archive and open the "en" folder (I'm assuming you're doing this in english). Now just drag and drop the entire "plugin" folder into the "_system" folder and your emulator is installed. Throw your roms on the sd card and you're done. I put my roms in the "gamepak" folder, but supposedly this is unnecessary. Plug your sd into the iPlayer and boot it up. Go to the homebrew option and you should see that pretty ndsgba folder you installed. Underneath you'll see the GBA.plg file with a puzzle icon next to it. This is your emulator and you can run it from here. Once you've run it once you can just run the rom files from the homebrew menu.
Bear in mind that while the iPlayer supports most emulators, it doesn't support commercial DS roms so if you intend to play commercial DS roms from a flash card you'll need a different card to do so.
Good luck and happy emulating
