According to Tom Waren, Senior Reporter from The Verge, who claims to have seen Windows Phone 8.1, a Swype-style keyboard is coming to the OS (although of course he did not say which version or when).
In the days of Windows Mobile the OS has multiple keyboard plugins, much like Android, but in the era of Windows Phone there has only been one (very good) choice (for western alphabets at least).
The Swype gesture-based keyboard is pretty popular on Android, and appears to be much in demand on Windows Phone, if the User Voice entry for the item is any indication, which has nearly 3000 votes.
If this does show up on Windows Phone 8.1 I suspect very few will be unsatisfied with the magnitude of the update.
Via Reddit.com