I like my Fire. Would I like to have the Nexus 7? You betcha. Am I going to run out and pick one up immediately? No.
If I had the few hundred extra bucks to just blow on a new fondleslab, I'd probably think about getting one. Not as a replacement for the Fire, but as a new toy to play with and I'd probably wind up giving it to the wife since she's been hinting towards getting something like that anyways.
I will admit to wanting new electronics gizmos when they're announced. Every new thing that gets announced (for the most part) is something that I want. But, I rarely get it. I just get excited about tech and phones and slabs and all these other wonderful toys. They're like legos to me anymore.