This in from "The" Paul Vigay, our favourite tech support bloke and staunch RISC OS supporter. After noticing that the domain name acorn.co.uk had expired, he made enquiries into grabbing hold of it. Slight problem however in the reply from Nominet...

The Internet Domain Name acorn.co.uk is a pre-Nominet registration. This means it was registered before August 1996 with the UK Naming Committee, Nominet UK's predecessor as the manager of the .uk Top Level Domain. Domain Name registrations made at this time were not subject to renewal, therefore the Domain Name will run until it is cancelled by the Legal Registrant.

Technically, does the legal registrant even exist any more? Certainly it doesn't seem like anyone's going to be cancelling their subscription any time soon. However, there may be a solution - just not RSN:

...there are discussions about bringing pre-Nominet registrations into line with the current Terms and Conditions of Nominet UK, but nothing definitive has come from this.

Source: Paul Vigay