I'm powering down my steem now, I feel by the time it's all powered down, it won't be worth much and Hive will have gone up a lot by then. Hopefully I have some time to move most of my funds over before Hive's price goes way up. I think an interesting approach for migration would be to shut the exchange for a particular token and just airdrop to corresponding users. The only downside would be if there was new steem users holding the tokens.