Currently I do not think we have an active converter for it, but you would be the first.
We can convert wordpress blog into xenforo posts. I would have to do some tests though, I can at this point not guarantee 100% it will work - or work well enough. If you have sample data for me I can go figure it out and show you the outcome and see if you're happy enough with it. And if you are happy with it, I can import it on top of the IPB->Xenforo import