Sorry for the delay in my reply. I have 7k miles now, the "whine" is probably a little less but still plenty annoying. I'm still undecided if I want to have 5th gear replaced, I'm going to take a two day driving trip in May and make a final decision after that. There still seems to me to be a downside to replacing 5th gear, a poster with the same problem on another forum said they had their 5th gear replaced and although happy with the work still have some "whine", particularly under accelleration, I'm not sure that's better.
My local dealers and Ford have been good to deal with and both are willing to replace 5th gear. The problem as told to me seems that for strength and lower cost Ford is using straight cut gears which are nosier than helical cut gears.
Waited a long time to buy a new car and a Ford, my 4cyl manual Jeep Liberty had almost 200k miles before I traded, so pretty dissapointing. I'm thinking of driving the Ford until the fall and trading, I'm going to look at the redesigned VW Golf when it comes out.