Image by LA Wad via Flickr
It seems in Germany some of the ICE trains also have WiFi too. Just like the Acela's on the east coast here in the USA and a few of the Pacific Surfliner trains that run along the California coast between San Diego and Santa Barbara.
Having used these in the past, including the Heathrow Express, it's nice to see the railways of the world recognizing that getting work done on a train is no longer just an amenity.
Via Rail here in Canada has WiFi as well!
http://www.viarail.ca/en/useful-info/onboard-train/wireless-internet
Wifi is on ultrahighspeed italian trains too since january 11
http://www.trenitalia.com/cms/v/index.jsp?vgnextoid=79a7118db57bd210VgnVCM1000003f16f90aRCRD