Will Cortana do her thing on other platforms?
When Cortana becomes available on Windows 8, Microsoft worries how the service can provide a complete experience if the Windows PC owner happens to own an Android phone. Ash asks, "But how do we get Android users or these other iOS users that use Windows to have a great experience?" Ash is the group program manager for Cortana on Windows Phone.
Considering that Microsoft's Bing search app is available for iOS and Android, it would seem to make sense for Microsoft to do the same with Cortana. While it might make sense, it wouldn't be easy to do. Rob Chambers, a group program manager from Microsoft Research, said that getting the program to work as "seamlessly" on devices running other operating systems, could be problematic. As an example, he pointed out that a phone running Cortana would have to always be running on on low-power so that Cortana can be ready at all times to spring into action.
For now, Cortana remains exclusive to Windows Phone 8.1, although there might just come a day when she is plying her trade for iOS and Android users. You can check out Marcus Ash's comments about sharing Cortana with other platforms, by clicking the video below.
source: GeekWire, @markguim via WPCentral (1), (2)