HAF, from my understanding, is a continually updated database of the blockchain that Dapps can use to access information in a more streamlined way. I am no developer but I am hoping that this will be much more searchable than the blockchain and who knows maybe someone will use it to train AI to help find things. To me, it is one of Hive's missing features. There is so much data on the blockchain but it always seems to fall into the abyss after the 7-day curation window.

The money side of Hive is also a great incentive and I am hoping that a whole economy will develop so that people don't feel the need to just sell their Hive to turn it back into cash.