So what to do? Turn down the offer? Stay and learn a new technology that I am not exactly enthusiastic about? Find another position elsewhere that will allow me continue in a J2EE role?
Any advice would be appreciated.
If I understand your situation correctly, you can either:
Stay where you are and learn to love .Net.
Move to another city, delaying the time when you have to learn to love .Net for a while (you said you'd be transferring to a J2EE role that would transition to .Net later on).
Find a new employer.
Let's talk about the move-to-another city alternative. Depending on your company, you might consider negotiating a Tuesday-through-Thursday on-site/Monday-and-Friday telework situation until your daughter enters college. Since your employer would be taking on additional travel expenses, you might have to give a bit with respect to your relocation package so everyone comes out whole. I'd think this would be feasible.
Now let's talk about your aversion to .Net. Your employer has established it as its architectural future. That being the case, it would seem to me that if you want to remain with the company, embracing .Net is a professional obligation. If it's one you're unwilling to accept, it isn't too soon to start looking for alternatives that allow you to continue developing in a Java environment.
Last issue: If you seriously think your manager is discriminating against you in favour of colleagues from his nation of origin, you might consider a discreet conversation with HR. While we in the United States consider discrimination to be a significant matter, other cultures figure taking care of their own is a primary obligation, so your manager might not have even considered that he's behaving inappropriately.
Be careful on this one, though. Your manager might have a very different perspective. It might be, for example, that you've been less than successful in hiding your aversion to .Net, and your manager has decided to award opportunities to more enthusiastic employees instead.
And no matter how discreet you try to be, not all HR departments end up returning the favour.
One more thought: With respect to finding another employer, the one you have appears to be unusually accommodating in terms of respecting your preferences and trying to find appropriate opportunities. I know a lot of managers who, had they learned that an employee was looking for other opportunities inside or outside the company, would have taken offence and retaliated.
The view from here is that your likelihood of finding a better employer, in the sense of a company that pays conscious attention to creating a positive work environment, is lower than your likelihood of finding a worse one.
Sign up for MIS Asia eNewsletters.