At first I assumed (like many) that this would mean UrT would become "better" in some way, but having read the entire thread that you posted Ron, I see that things do not look great at all. Making the whole thing closed-source means relying on FS to patch exploits, and we all know how long they take to release new versions.
I can't see that many of the "major" clans will transition to 4.2/HD, mainly due to the reasons you posted - they've all got their mods to make administrating their servers easier, and HD will take that away from what I can see. As you mentioned too, no /save and /load in jump servers? Only the most pro jumpers would ever make it through a map.
One question I have Ron is this: how does the game you're developing relate to Urban Terror and ioq3? Is it like a mod to UrT, or is it a game built to use ioq3 like UrT currently is? I guess what I'm getting at is, is it possible that your game can run directly on ioq3, and can it be modded so that it's not just Zombie, but rather a replacement for UrT, with all modes available? I know such a thing would be a huge undertaking, but at the moment I don't know what your vision is for your project, or if this is something you're doing or planning. If you can, I'd be interested to know where you think 1up can go from here, as running 4.2/HD servers seems to be out of the question at the moment.