Chessfriend.com is running an interesting correspondence chess tournament, the Alexey Tsvetkov Memorial. The event is a KO format, two players play two games against each other, colours reversed in the 2nd game. The time control is a Fischer clock 20 days plus 2 days per move. In case of a tie, the lower-rated player proceeds to the next round.
With server chess and this kind of time control a KO format actually seems possible. In postal days a KO event would probably have lasted for decades.
There have been some hot discussions on TCCMB and elsewhere about the two serious correspondence chess servers (the others attract the casual gamer). While I am the developer of the ICCF server, I actually think it is healthy to have more than one server. A tournament such as the Alexey Tsvetkov Memorial can be considered experimental, but if it is a success I can imagine that ICCF will consider running similar events in the future.
I am actually participating in the Alexey Tsvetkov Memorial myself. I managed to proceed to the next round after two exciting games.