Do I need Device Cloud to make two remotely located Arduinos talk to each other via Xbee Wifi?

Hello Digi-community!

I’m working on the topic of “remote presence” and have so far built a set of tangible objects that talk to each other via Bluetooth. Here are some pictures, video and other material:

In short, serial-in (pressure or heartbeat) in one location causes an effect in another (ex. leds gradually light up). I have used different Arduinos (Uno, Fio and Lilypad), programmed with Arduino IDE and connected to each other with Xbee-modules (of Series 1).

I tried replacing the regular Xbee Series 1 -modules with Xbee wi-fi:s, and everything worked seamlessly – yet only when the modules were both connected in the same local network.

Now I wonder whether it is possible to make them talk to each other from one Wi-fi module and network to another, for example from Finland to the USA and back?

Can this be done directly (from device to device) or would I need to pass the serial data through Device Cloud?