BT offers per-minute plan to businesses: BT OpenZone has been charging £85 (US$135 or so) for unlimited monthly access. Feedback from businesses has caused BT to adopt an iPass-like model in which businesses commit to a serious amount of usage but then pay only £5 per month per user and 5 pence per minute, resulting in an average much lower charge for a larger workforce.
At the same time, the report says, BT will probably withdraw its unlimited plan, and offer plans like it does now with 300 minutes for £20.
What is probably most telling about this article is that BT Openzone's focus is still clearly on big sales to big corporates. They really don't seem to be interested in ad-hoc connections or freelance/SMEs.
Now arguably subscriptions to big corporates is easier business, but it doesn't work unless you have the coverage.