Most assuredly not. I have a large investment in x-wing in terms of time and money and people actually play it. I will play Armada when I can but still carry my x-wing pieces for pickup games. Tie-in or escalation battles would also be fun, using the two games in concert. In the long run, while big fleet battles appeal to me more strongly, there will always be a place in my heart for the dogfight. Heck, even if Armada completely eclipses X-wing in terms of playerbase(I don't believe it shall), I'm not going to get rid of my minis and attendant paraphernalia.
Now the real question is "how badly will Armada crimp your gaming budget on release", because it looks like there will be a 2-3 month window where I'm buying enough Armada stuff that I can't afford more x-wing(the "must have one of everything and two to three of everything good" effect). Which is fine, given how long I've had to put together my x-wing forces.
I'll be building both fleets, if just for the pure and simple fact that it will be easier to get someone into the game if you can plonk a pre-built fleet down in front of them and get on with the 'splaining.