There seems to be an updated Blue & Me on the way - certainly on the Twinair which seems to launch in September:

"Finally, Blue&Me – TomTom, the latest evolution of the Blue&Me system, will be appearing on the Fiat 500 along with the new TwinAir engine. Blue&Me – TomTom is a fully integrated infotainment system that lets you manage telephone, navigation and useful driving information functions using a practical colour touch screen interface. Furthermore, with the launch of the solution on the Fiat 500 a new mediaplayer feature will be introduced that further strengthens the Blue&Me - TomTom proposition. Blue&Me – TomTom is conveniently and elegantly accommodated on the dashboard of the Fiat 500 to combine the safety and convenience of an integrated solution with the flexibility of portable devices. The device is the result of a partnership between Fiat Group Automobiles and TomTom, the European leader in portable navigation systems, and integrates with the car’s other systems via the Blue&Me system developed in collaboration with Magneti Marelli."

Italiaspeed

Sounds like the Italiaspeed article/press release isn't strictly accurate then?

Having said that I thought that the nav port in the 500 was for something other than TomTom - or has this changed?

That's strange, all the info I've read or got from the dealer says that the B and M Tom Tom does not integrate with the 500? It will draw power from the port but not communicate with the car systems. Fiat dealer (Marleybone) told me that a new version for the 500 was due in September which would fit with the article above. Are you saying you've got the existing B and M tom tom nav working with the systems on the 500?

Ah, that explains it, thanks 
I'm just a humble fiat 500 imposter but I have a port!