Here are some salient points about Minion:
- Will work on Windows, Mac and Linux.
- Has an option to auto-update, set to "off" by default.
- There will be a premium version, but the only difference will be that premium users don't see ads. In contrast to the Curse client, the non-premium version of Minion is not crippled, and will have an update-all button and full download speed.
- If an author enables donation requests, they will show up in the updater.
Most interesting to me is the module system that the client will support. There's going to be an API in Minion so that anyone who wants to can write plug-in modules; for instance, Curse could write a module that would let Minion users update addons from Curse in Minion. They could show their own ads, and make their own decisions about whether to enable/disable "premium" features for the module. Security concerns for third-party modules are addressed here.
WoWInterface is asking that feedback be left on their MMOUI Minion forum. Without having used it, all I can say is the UI looks a little iffy (somewhere between Curse and Matrix in quality, in my opinion) - for instance, Mac apps don't generally have menus under a window's title bar. Anyway, I'm looking forward to giving it a spin, and kudos to the WoW Interface team for not crippling their free client.