This is, at best, misleading. As of the 1st July (today) ALL mobile operators in the EU will be forced to abide by the EU roaming regulations as determined in September 2008. In the case of data rates the maximum chargeable rate established by that regulation is EUR1/MB, which is substantially below what 3 is charging. So we can anticipate that all of 3's competitors will be imminently slashing their roaming rates.
CLARIFICATION: the EUR1/MB is a wholesale rate, not a retail rate. For all the other services covered by the new regulations, a retail rate is mandated, whereas for data it's only wholesale. Nevertheless we'd expect to see substantially lower rates from the competition imminently as a result of the lower wholesale rate. If not, surely there's a requirement to mandate a retail rate for that too.
Of course all of this makes little difference to the average consumer for whom all of the prices quoted, including the new EU mandates maximum of EUR1/MB is still prohibitively expensive. Average Joe still won't be taking his dongle with him on holiday. Not if he has any sense.