This is interesting, and I found it interesting 3 months ago when the article first came out, and a week later, when I bumped the thread.
Evolution in action: Transition from egg-laying to live birth in lizards. Message 1
What would be interesting to know is if future research can identify the mutations that make the difference between the slightly "egg retaining" mothers and their viviparous cousins. Also, it would be interesting to know if egg- eating predators have been identified in the "viviparous" area, as that would provide an obvious strong selection reason behind the transition.
Here's the
abstract. They were mainly researching the nutrition problem.