ZDNet UK is reporting that there is strong interest in providing WiFi access on train cars throughout the UK.

Today, there is already a company rolling out 802.11 access in the stations, but the future may include the rolling stock as well.

Frankly, I would appreciate it as an occasional visitor. However, I found the GSM/GPRS coverage from Edinburgh to London (admittedly a high-use corridor) to be quite adequate for most needs in November when I was there.