I still don't have the option to send directions from Maps to my iPhone or iPad. I thought that it was enabled in DP4 for all (DP1-DP3 seemed to be hit and miss). Does it only work on iDevices running iOS7?
If your iPhone and iPad are on iOS 7 and it's still not working my guess would be that you don't have the iOS 7 SDK installed because send directions to iOS 7 devices has been working since DP2.