Comex released today BannerBomb v2 for the Wii System Menu 4.2. From what I have read, it works great on 4.2 E/U Firmware. But give a try for yourself and let us know your experience with it.
Go to the official site (linked above) if you would like to help test it.
To quote: Compatible (in theory) with 3.x-4.0
1. Get a SD card. If it has a private directory, rename it temporarily, e.g. to "privateold". Having other saved channels on the same card will screw it up.
2. Download aad1f_v102.zip and unzip it onto the SD card.
3. Get a DOL or ELF and put...