Nominet Get ENUM as well as '.UK' TLD

Nominet have been awarded the contract to run the ENUM registry for the UK:

So management of the .uk domain and enum is now under one roof, a not-for-profit agency.

This really does make sense, but can you tell me whether this means that people can go direct through the internet via their ISP or will they still need a provider such as Skype?

Skype is really the oddball, as they don't use SIP or enum, it's just a completely closed VoIP community. In the general VoIP world, it's possible that your ISP could also be your ITSP (Internet Telephony Service Provider), but it's also possible that your ISP and ITSP could be two different companies. All ENUM allows is to map URIs to conventional telephone numbers, you still need a network infrastructure to carry the calls.