I'm not too learned in net code, but isn't it possible once a connection is lost all players would do an autosave and they could just rehost from that point? I made no intention to over simplify it, but the point is made.
How would the disconnected player receive the autosave?
I don't see where is the problem.
When i was playing CIV 4 it was possible to continue a multiplayer game from the save file.
Its not about reloading from a save, its about loading into a live game.
What is being suggested is possible, as far my coding experience tells me, but it would be difficult to, relinquishing control to an AI and back wouldn't be too hard, you can do that in Single player by quitting and reloading a game as another person. My problem with this would be, a player D/Cs (disconnects) on purpose and lets the AI 'fix' his stuff, getting upgrades, research, etc, that he didn't think about.
The fact that AI takes control in Sins makes it WAY easier than say in, Warcraft where your allies get the split of your stuff.
As far as making a autosave and reloading it once the disconnected player returns, this doesn't work because if the disconnected returns much later, causing a large amount of time to be undone, players would deem it as unfair.
Uploading information from the 'host' to the D/Ced and R/Ced player would be possible, but depending on the map size, how late in the game it is, how many ships, etc, could take awhile, but would be well worth it to reconnect.
As far as my suggestion goes, what if you could host a savegame as a map? Kinda like in Warcraft 3, everyone has to download the map from the host, why can't a save be used as a map with all relevant and important information in it? Ex, player credit, metal, and crystal amounts, researches, ships and positions, etc.