The Land cover is basically Generic Model/Woman X with red hair. If it wasn't Land's work, it would look like a parody of Land's work. The Raney cover is the best of all three but that's not saying much. At least none of them look like Scarlett Johannsen (a non-exactly inspired casting choice IMO).
I'm actually looking forward to this too. I've become a fan of the Black Widow in the last few years, so far it seems she's been able to maintain her dignity despite all the cross-overs she's had to go through. Not many Marvel characters can say that. I like her with Bucky too. The fact that he's really 80something (something often brought up) and she's really 70something (something that's not) and she's the only one who calls him "James" are nice twists.