Why is it every other source says we'll have a V6 option, this one source says "A base model with a V6, however, seems unlikely to appear from what we hear"......and everyone instantly believes that?

There's every indication that a V6 SXT (or similarly named trim level) will be offered in '09, regardless of what THIS one source says.
This car is special, unusual, and Dodge's approach has been likewise. Instead of coming out with the base models first, Dodge lead the reintroduction with the "most beast" they could unleash right from the get-go first. It was intended to get notice and great reviews. It's done both.
Now that the "big'un" has been introduced to the public, the "little brothers/sisters" will be sure to follow closely behind. It only makes economic sense for Dodge to do so.