On the downside? That these will all be single disc editions. And we don't yet know if they'll be region free, so importers without Region B capabilities might want to hold off, or go for the US equivalent - the 10 disc Marvel Cinematic Universe Phase One Avengers Assembled Movie Collector's Set currently at $152.99, down from $219.00.
Again, it's not yet clear if those discs will be region free, so importers outside of the US should again be cautious.
I'm not picking this up as much as I want to. I already have the other movies (Thor/Cap in 3D) and I'm pretty sure that the discs won't come with cases. Disney likes to do that with their "boxed" sets.