I know that he's working on this, just didn't released anything yet (not that I'm suspicious, just saying...). Though, Sorg made many other additions and fixes (I really like his version of BootMii, which allows to Auto-Boot from USB without any SD/Priiloader needed, NTFS-Support, etc.).
You sure it can autoboot without priiloader? I've never used uniiloader (I've been meaning to) but IIRC it uses IOS253. Wouldn't u need priiloader installed to be able to autoboot IOS253/uniiloader from USB? The only way I can see it not requiring priiloader to autoboot into uniiloader is if sorg also installed something to boot2 on capable wii's, but I doubt he would've done that... I mean, nothing beats bootmii@boot2.
And, are you saying that he's trying to make an (open) Banner-Player for the Wii? I know that there is already a
project which does this, and shouldn't be that hard to port according to the owner, but wow...that would be impressive. Though, and I'm sorry to say this, but imo, no loader would be ready to use this, and if you would modify one, it would look half-baked (except WiiFlow, but the memory there is pretty full already, so dunno if possible). Doing this would require a new layout with the banners in mind, in my opinion.
This would be an awesome feature, but I agree that memory/speed is a concern of mine regarding adding this... especially on emu-nand usb-loaders which are slower to begin with. If it can be added without making anything slower, I say why not... but that's a big "if"