Over the years i used to think there was loyalty in employment, but there really isn't. You could be a loyal employee for years or whatever and feel like you have a place at that company indefinitely. And then overnight things change and that employer can show you the door with no warning. So its a two way street in my opinion. You need to worry about YOU and YOUR career. YOU advance yourself. Handle it professionally and don't burn a bridge. Offer two weeks and move on. Follow YOUR dreams!