Yeah, it says world premiere, but they only have a deal with Vodafone to collect the necessary GSM signals to calculate the traffic in an area. So, it looks like you can buy it anywhere, but only use it where there is Vodafone service.
The service will initially only be available in the Netherlands, and will offer external routes, that according to the data collected, should be faster. The first device to be blessed with the new HD Traffic tech will be the TomTom ONE XL HD Traffice, which is exactly like the ONE XL, but add a SIM card to get the traffic data with.
TomTom will shortly be offering add-on’s for their current devices, and presumably software upgrades to go with that to make use of the new hardware. This new technology will hopefully bless the UK by the first half of next year.