Qt without native UI isn't Qt. I am very interested to see how they will manage to handle the difference in UI concepts between the three mobile platforms.
However, this is not all it takes to escape the uncanny-valley feeling. For example, the dialog layout still has to be correct, and lots of developers don't make the effort to achieve this.
How many times have you seen an app that is suppose to look 100% like an iOS app badly ported over to android where everything "works", but doesn't fit in.