(hope this isn't a repost)
In the Feb 09 issue of Car and Driver, they did a comparo of the above cars. It looks like the review isn't online yet. The winner was the Fusion Hybrid. The overall rankings were as follows (all hybrid versions of course):
1. Fusion
2. Camry
3. Altima
4. Malibu

(My mom owns an 07 NAH) I will say many of the remarks about the NAH are on the mark but it was the fastest in all the acceleration tests and had the 2nd best observed mileage. The Malibu Hybrid, not surprisingly had the worst mileage and was much slower.

I do wonder if the review would've turned out differently if they were more equally equipped. The NAH had the expensive technology package (w/nav) which really jacks up the price. Also, they didn't give it much in terms of bonus points for the $2350 tax credit. In fact, they didn't even write about it and gave it just 1 extra point for rebates/extras.