Speculation of course, but you know how much I like the exercise
I don't think Gwent will be like Hearthstone. I don't have much solid evidence for that though other than this part of the description:
- Powerful spells allow players to control the weather and affect units on the battlefield.
You could imagine that different spells could effect your units differently, adding a layer of strategy, variation, replay, and all that good stuff that HS frankly doesn't have at all. M:TG doesn't have that either, but it has many other things to make up for it, in particular
wildly different card decks to play. I wouldn't expect such wildness from Gwent though, so at the minute I'm placing Gwent somewhere between the two games. The concept as described definitely has promise, I can't in all decency recommend trying HS though. I'm not taking this opportunity to bash that particular game, just being thorough in my description, and I found it an extremely weak game, with zero originality or unique contribution to the genre.
Rage Frenzy... for all we know Gwent will play a bit like that too, I mean it appears a bit more like
battle lines doesn't it? M:TG isn't conceptually like that, you are warring Mages who conjure various spells that sometimes include physical warriors, sometimes don't. You could imagine HS to be a battle lines game, but it doesn't play like that either, its more like M:TG, with a main character whose death is the endgame. We do not yet know if Gwent has such a focus.
TL/DR I remain hopeful for Gwent, I still play M:TG occasionally, and HS has now been uninstalled.