I think most folks in the mobile media business would agree that one of the key inhibitors for uptake of our content and services are the unpredictable nature, from an end user perspective, of data charges.
The apocryphal story of the early adopter with their new 3G phone making heavy use of "free" video clip downloads for the first month and ending up with a bill 10 times larger than normal is I suspect going to figure almost as much as the "crazy frog" subscriptions fiasco when we come to look back on the unnecessary barriers this industry has thrown up in front of mass uptake.
Three's announcement of their new X-series, if a little short on detail at this stage, is a very encouraging step towards the "norm" for mobile data access to be broadband style flat rate under some set of fair use conditions.
This is the second operator to go in this direction in the UK - with T-mobile being the leader in the space with their "web-n-walk" series. Vodafone do have a flat rate data tarif but it is very expensive and aimed at business users - more or less irrelevant in the consumer space.
Now I don't for a minute expect this to be a panacea, this is Three after all, as nicely captured by Carlo Longino over at MobHappy. I fully expect it to be bound up in fairly restrictive "fair use" caveats which plenty of folks will trip over - but it is a great step in the right direction!
This will certainly be key for the uptake of richer browser based services on mobile - as enthusiastically pointed out by Ajit over at Open Gardens!