Am I right in assuming that I will always need an Apple Mac to create and manage my iOS developer provisioning keys and certificates and this will always be the case even when using Icenium on Windows?
Will Icenium provide Windows platform developers the ability to design, develop, build and deploy for iOS and publish them to the Apple store and not need access to a Mac or XCode?
No, you do not need a MAC. You can generate certs from Windows as described here:
If you don't want to use Ion for testing on iOS then you have to configure your mobile provision on Apple's site but that can be done from Windows via a browser. The steps to do that are also included in that write up.
So just to finally clarify. You are saying that Icenium, when publishing to App Stores is made available, will allow apps to be deployed to the Apple App Store and the developer will NOT require an Apple Mac or Xcode for any part of the process ?