Interestingly Windows Phone 8.1 already has a Swype-like keyboard which works really well. I hope they will include it in Windows 8.1 or maybe Threshold as well.
It's a good development for iOS and WP to have more flexibility without comprising the essence of what they are.
When I got the Lumia 635, I didn't know about the swype-like functionality. I used it from time to time, without thinking, but never noticed it until someone else pointed it out.
It works well, and would be nice on the Windows tablets.