The question's already been answered (yes, but good luck getting it out of Bond), so I'm just gonna give my thoughts on the concept itself.
My only concern would be whether or not red card support would break retail cartridge support. Otherwise, you're still in the same boat as it stands now, with having to reboot and switch modes depending on which media (red card or retail cart) you're using. If we could have use of both types of media in the same CFW, then I'm all for it.
What we're more likely to see is an overhaul of the GW CFW (GW Mode = CFW, just DRM-regulated) that will implement some of the advancements that the homebrew scene has added to their free CFWs. There are three main things that I'd like to see in the next GW update.
1. Downgraded MSET support for O3DS/2DS running 9.0-9.2
2. Sig checks removed from Classic Mode (so you can use retail carts with SDF)
3. DSiWare/GBA support (probably only addable to Classic Mode)
I personally like having my Gateway, and would probably still buy one if I was just entering the 3DS scene now. Having double the storage space for games means that I can have a far bigger on-hand library than relying on a single SD card. Plus, the convenience factor of the GW's faster and easier way to load games than CIA installation allows me to try a wider variety of games outside my norm and feel less guilty about prep time spent when they suck.
tl;dr: GW improving itself with public CFW features is the more likely outcome. GW is still money well spent in the current CFW climate because of convenience.