Many recommend having the newest tyres on the rear, even on a front wheel drive car. I'd wait until you need new front tyres, then rotate, putting the new ones on the rear. This might be sooner than you think tho', as although the legal limit is 1.6mm, tyres are past their best at 3mm.
If you are planning to change the make or type of tyre, then rotate now so the all 4 need replacing together.