The issue with DOTA is that its audience is self-limiting. You're locking 5 strangers together in an hour long game where failure is heavily, heavily punished and you're penalized for leaving early.
Where are the games for those of us who loved Half-Life and Portal? The last thing I want to do at the end of a long day is be yelled at by college kids and teenagers for an hour.
Sure, DotA 2 is a rare F2P MOBA that's fair. I mean, I find most of hero kinda meh, but I do appreciate their business model.
But a Card game based on DotA can only mean one thing:
- A F2P game. I can't imagine there being a different model
- A collectible card game. They won't innovate here.
- Buyable cosmetic, but not community made. It's not like they'll allow visual clutter on your cards.
I can't speak to the F2P card game because it does not exist yet.