Kinda hard to predict. Before JS, STEEM price was dropping, even when Steemit Inc. stopped the monthly sell of their stack to fund their activities.
On this basis, and with no major changes for now, there's no reason for HIVE to not follow this trend. There might be an increase in price at first because of novelty and people selling their STEEM for HIVE (but for sure there won't be 100% of STEEM selling going to HIVE and there will be people dumping HIVE because of airdrop "free-money", especially if the price increases), but currently, there's no fundamental reason for HIVE price to not follow the trend of the STEEM price prior to Februrary the 14th.
RE: What will happen to the prices of HIVE and STEEM?