In the spirit of sounding like an idiot, there is nothing wrong with wrong wheel drive for most average drivers, so the fact that most Alfas come that way isnt going to sway the average car buyer for or against the new models, if anything, it would increase their perception of the car in a more favorable manor.
It has been noted time and time again that so many of the knuckle-head drivers in America belive that FWD is going to be better in the snow, better on fuel economy, and cheaper to buy, etc... If Alfa sells FWD products for the most part, it won't have a negative effect what so ever. It fits into their mindset, and thus, they will buy more and more of the products.
If they can price the cars accordingly, as I have said before, they will sell well. The 159 will be a good option to a Saab 9-3 or Lincoln Zephyr (or whatever the hell they are going to call it now), and may take some sales away from the BMW 325i and Mercedes C240.
The same can be said about the Brera convertable, which would probably be the middle ground between the VW Eos and Volvo C70. The Alfa would probably be the sport alternative between the two, hopefully with a baseline MSRP starting between $32K to $35K. Sporting types will probably spring for the Alfa for it's stronger looks and presumably more sporting attitude, but I think only the VW would challenge it for most folks.
Last but not least, the 8C will be the stand-out model for Alfa's return to the US. I'm not completely sure what the size of the car is, or what exactly the performance figures are, but it appears it will lie in the middle ground between the S2000 and 911. Unfortunately for the 8C, it may have to compete with the Corvette, Boxster, etc generally viewed as the kings of the sporting world here in the US. The 8C will be a reputation builder for Alfa, but the 8C must build a reputation for itself at the same time.
Everyone needs to give Alfa a chance before they completely write them off as a no-go company. It has been a long and well-thought process to re-introduce their models to the American market, something that has been debated for nearly the last decade. They wouldnt come here if they didnt think they couldnt make money, so let them do their thing, show off a few models to the press and the public, and then make a good guess as to where you stand.