I haven't be able to notice anything other than the way it is played, the hearthstone userbase is really huge, I can see many wanting to switch over if they realize they can have another income stream by doing the same thing they are doing now without ever controlling their cards in case they want to "sell out" and "retire". 

For gamers, being able to buy in and have cards that will never be created again would be pretty cool. I remember some cards of season 1 hearthstone still being cards used today too cause they remained pretty good cards over time.

For collectors, they also have "diamond" cards which are 10x harder to get than gold. Not sure what the "mythic" one is, which one more exists in the unsold packs, my guess was a diamond legendary but not sure.