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.
There are various reasons why the concurrency was limited, on mac for example it's actually a technical limitation with the Cocoa APIs for file downloads. What I expect you'll find is that with our new infrastructure we will have and a lack of download speed is that you'll be able to max out most connections even with a few concurrent downloads.
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.
Our goal is to improve everyones experience, modders and users alike. Working together I think we can do that.
After reading through this and hearing that Curse is working on mac support. I kinda find that hard to believe. Considering that Curse dropped support of the mac client last year, i find it really hard to believe that its being worked on again since it was left in the alpha stage and never touched again. Hell even the client download page blatantly states that the Mac Client is unsupported. I know that some of the devs and staff at Curse use macs but still, to say your going to work on it again later this year after saying that support was dropped 8 months ago via curse news. This news strikes me as hrm, should i trust that curse is going to follow through and recreate a mac client and maybe down the line a linux client. Im not so sure about that.
I was actually the author of the original Mac client, so believe me when I say that dropping official support for it was hard on me too. With that version of the Mac client, we didn't have a big enough user base to justify continued work on it, and I had to move on to solving our infrastructure issues. It is still a functional app, admittedly with some bugs, but I use it myself when I go play WoW. That being said, the market has changed. The two major factors that will have us back with a brand new Client for OS X are Minecraft support and CurseVoice. With this we plan to update WoW support for Mac users as well. Personally I'm very excited.