We are currently working on the iOS 8 support, even though you should be able to deploy on such device already. There are some lapses like the new icon sizes that we will have to add and if you have anything in mind I will be glad if you share it with us. We have targeted the iOS changes for the upcoming release at the end of the month, but you never know. Sometimes unexpected changes arise. Here is a link
to our roadmap notes where you can find more information.
Regarding the Cordova 3.6.3, I would like to ask you if there is anything important in that version which you would like to see. We strive to keep Cordova up to date, but most of the time we add support for a stable versions like 3.5 / 3.6 etc and I cannot specify a time frame.