The "pro-American Made in the USA" publicity would only be good for Apple IF a significant percentage of their products were actually assembled in the USA. However, it seems that since this is only limited to BTO iMacs, that is a very small percentage of their goods, and thus the Biased Media will absolutely crucify Apple on this by making headline Tech News stating: "Apple only assembles less than 2% of their total products in their home country. The other 98% is built in Communist China! Shame on Apple, how unpatriotic! Apple is heading to failure just like DELL and HP and all the outsourcing Devils!"
In summary: Apple should not even mention this or should not even respond to these rumors (of products assembled in the USA) at all. It can only backfire on them at this point.
P.S. -- did I mention that I just ordered a BTO iMac 2012?