CarbonX13 is completely wrong.
There is really 1 big reasons this is not done. The reason is simply because nobody has completely reverse engineered the banner format and written a player for them. We already know how to take them apart, play the sounds, display the images. It is the correct laying out and animating all these images which is lacking. The resolution is not an issue, as even the lowest level wii GFX api allows scaling of images.
Once this gets done, and there is actually a way do display a working, animated banner, will come the second issue... The big delay involved in reading several banners. The way the system menu does it, it reads the banners for the current page and the next page. So, it stores 24 banners. Once you press the button to move to page 2, it reads ahead and loads the banners for page 3.
This works pretty good for the system menu which is reading 1 exact file ( already decrypted ) at a time from flash memory. Then it turns that file into a banner. However, to read a banner from a disc game, the loader must mount the game. This involves telling the cIOS to mount it, then the cIOS searching the HDD for the correct game, then actually opening the file, then reading the filetable to find the banner, then reading the banner ( which must be decrypted in IOS - this happens quickly, but is still a necessary step ), then turning that data into an animated banner, then closing the disc.
For all this to happen for every single game, every single time a banner needs to be shown, Im guessing that you will have a noticeable lag in the loader. And people with 500 games might as well not use that loader; it would take 5 minutes to get to the games in the middle of the list.
