At present the long term plan is to strengthen the links between the Missions Depot and the Addons Depot, so yes, hopefully we will host all the addons for all the missions that we host.
This does raise complications - for instance all the addons we host will have to meet minimum standards, such as having OFP tags. (This will mean that the mission's addons will not cause conflicts with addons already in your addons folder.) These standards are likely to rise significantly when ArmA comes along. So if you want your mission to be hosted at ofpec, only use top quality addons.
The objective of the Missions depot is not necessarily to be the biggest mission repositary for ArmA, although we would like to be. The objective is to be the best. That means missions that work with addons that work.
We have much to do to rebuild ofpec and its obviously necessary to prioritise. The addons depot was the least active before the crash and is also the heaviest depot in terms of things like bandwidth. Consequently the missions, editors and intel depots have been given a higher priority.
We are working on a resources board for the Editors Depot in the similar way to the Missions Depot and it will be launched when its ready. The timescale is currently being measured in weeks (rather than days or months).