This isn't really a hard answer
1. Keep it as a plug-in, just because CS can't work on it, doesn't mean someone else could pick it up in the future and continue on it.
2. Make a software render only CS version that someone else can work on later in the future.
Don't get rid of the code, leave it up for anyone who wish to work on it.
The decision on the software renderer has been made already a few weeks ago. We will keep it but simplify it (no lightmapping).