I think there's just a bit of over reaction when it comes to this topic. I doubt it will play a key role in the game, and seems more of a love it or leave it aspect.
As long as they take it a bit more seriously than fable did, I don't think it will be a bad feature to have.
Also, I don't think it's fair to basically say it's using an idea from fable. I mean, marriage is a real thing, and I assume the characters in TES universe have been marrying for years. Just because fable used the feature in their game recently, doesn't make it their feature. I mean...harvest moon had marriages (though, they were pretty big features in the game). Let me know if there is some deranged female mayor with dark secrets; though, then I guess we can consider differently (off topic slightly: Wouldn't it have been cool if Fable really had the marriage concepts added announced originally?)
Overall, I say it'll be ok, and easy to ignore.