Forgive me if this was answered already, but I went back through the thread and didn't see it mentioned, and am curious about a couple of things.
First, we know that Curse needs various features that they can reserve for premium use, and from the way I understand it one of those things is limiting the number of mods you can update at one time. Somebody in this topic even mentioned that. I'm curious how exactly this works with the concept of a modpack, though. Modpacks are treated as a single entity, and use their own version numbers as certain groups of mods are updated. I think it would be havoc if the Curse client would only allow people to update mods individually if they weren't on Premium, and were actually allowed to run their games this way without fully updating the pack. Slowpoke said in the main post that bandwidth isn't going to be limited, but that doesn't imply that downloads won't be limited, so I think it's important to clarify how this system will work with modpacks involved.
Second, we initially heard that this partnership would result in an open API that would allow others to create clients to take advantage of this mod repository, probably indirectly referencing competition such as Technic or other launchers out there. But all I've really heard in this thread is of a "limited API for end users". Does this imply that a) the API, if one is even created, will be inherently limited, and/or b) that non-end users would have to register for and obtain an API key or some sort to get full functionality, similar to how social media sites do it? And if it's the latter, is it going to cost a fee? Would even the "limited API for end users" require Premium? It was mentioned that ads could be added to the launcher in the future, and I doubt Curse would want to freely allow other launchers to exist which would take away from that income while still taking advantage of their services. I'm also curious when exactly this API, if it's developed, would become available after the launch of this new client.
This is supposed to be the platform that modders will use in the long-term, so I think that knowing how this will work in the long-term are the kinds of answers we need to know.
EDIT: I don't want my rather blunt questioning to imply that I'm mad or anything, I just genuinely want to know what this all means for people. If this system works as well as everyone hopes, then I actually get a benefit out of it. Currently I don't get anything from having mods in modpacks, but through Curse I would/do. I can't complain about that aspect, and hope this platform can be a good thing for modders as well as users under the right circumstances.