The Corvette is also General Motor's halo car. Therefore, the Viper would not be General Motor's halo car (I stress halo car). As a result the Viper would get killed.
But GM doesn't have the money to spend on turning around Chrysler. Pontiac and Buick also need to be turned around.
Or GM could just let Dodge die and take a good chunk of Ram sales, nearly all Charger/Magnum sales with Zetas, a good chunk of Caliber sales with the HHR, Durango sales with the T900s, and not invest any money in Chrysler.
Having the Charger, 300, G8, and Lucerne makes no sense. When there aren't LX cars on the market, the natural fit for LX owners is the Zetas. Therefore, GM would get nearly as many sales out of half as many vehicles. Hummer can take Jeep's sales (all Wrangler would go to the H4, a good chunk of GC sales would go to NG H3). Chrysler is certainly more sporting than Buick at this point in time.
The best thing for GM to do for GM's sake is nothing at all. Many of Chrysler's sales would probably go to GM considering the products GM is going to be putting out that are similar to the current popular Chryslers. GM also would have the daunting task of not only dealing with product issues, but dealer issues, plant issues, and personnel issues. The fact is that it's way too big of a project for GM to take over. Some private investors should take over Chrysler and give them the funding they need. GM cannot provide the funding that Chrysler needs to be turned around, and I see GM being put up for sale in a few years if they do in fact buy Chrysler.