I can report that Irish Rail are conducting trials of Wifi on the Dublin Cork route using 3G only. Borrow a computer science student, get a modem from the 4 networks and its easy enough hack something up. Though IE really need to be looking at something like this
http://www.icomera.com/m400_overview.php?id=1&p=1
It works but there are 3 major blackspots en route. 3G coverage is rubbish outside populated areas. Other routes ruled out due lack of coverage
Talk of filtering as well to block youtube, to avoid the connection being saturated with unproductive traffic