Mustang is middle-ground, so it wasn't mentioned in that article of polar opposites (big trucks & suv's vs small cars). Mustang sales are down a bit this year, but not unexpected in a body style that is now in its 5th year. The 2010 refresh and new powerplants should help, and a major overhaul in the 2013 model year will hopefully spark a new wave of buyers.
I work at a big volume Ford dealership. Our #1 seller now is the Focus, followed closely by the Mustang and Fusion. The Escape and Edge sell well, too, and we're always sold out of hybrids (Escapes and Mariners) due to crazy demand. Ford is doing a great job shifting from trucks and SUV's to small cars in the short run, and we already see a big difference in the orders they're filling for us and shipping. It'll only get better as more models (from Europe) arrive to add to the offering at the local Ford and Mercury franchises.
We still gotta unload a bunch of idle trucks and SUV's, though. We used to sell 30-40 new F-series trucks per month and typically had a 2-3 month supply in stock, but now we sell less than 10 per month - even at employee pricing and record rebates. With 140+ on our lot, that's over a year's supply! And with the new '09 F-150 coming soon, who's gonna buy leftover '08's? Ford and its dealers are gonna bleed bad to move out remaining new '08 trucks. I checked on the rebate for a new '08 Lincoln LT pickup (F-150 in Lincoln guise), and it's $10,250 for me currently (factory rebate and owner loyalty rebate). Plus the huge discounts to unload these and they can be had for about $15K below MSRP with few buyers considering them. Crazy!