Kim Clinkunbroomer shared on Google+ that you can now work with your mobile call extensions within conversion optimizer in Google AdWords.
In short, Kim spotted a new call out in the AdWords console announcing a new feature that links to this help document. It says, "More powerful call conversions: Now use Conversion Optimizer to maximize results from mobile call extensions. View your call conversion performance in your regular conversion reports."
Here is a picture:
Andrew Rulnick explained in the comments on Google+:
Consolidating mobile click to call and manually dialed actions into conversions and estimated cost of conversions. Conversion optimizer now uses this data to improve ROI.
Forum discussion at Google+.