Some signs point to Dodge being the next major player, with the Neon SRT-4 due out soon...Though rumors say the AWD Focus is due here in late spring/early summer. Don't know whether a turbo will be under the bonnet or not.
Same reason you don't see major sponsorships from non-automotive companies... not enough return on investment. Since rallying is little known in the U.S. (though it is growing again), Ford is not about to dump a whole load of money unless it translates to sales. So they spend their motorsports budget on NASCAR, CART, drag racing and off-road where there are a lot of U.S. fans.
That said... look for a major ProRally effort involving a Ford product during 2003.
That is my understanding. The team in question has secured American sponsorship, and that sponsor would prefer to see the team in an American vehicle. Ford is the only American manufacturer that fits the need.
Negotiations are still under way, but I'm sure something will be ready for announcement by Sno*Drift in January... or by Rim in May (2nd event on the tentative SCCA schedule for 2003).