Telegraph from August last year claims they will be annonymised:
...The records will be anonymised but will include details of medical conditions, reports the Daily Mail...
http://www.telegraph.co.uk/health/healthnews/10250585/Jeremy-Hunt-plans-to-give-anonymised-patient-medical-records-to-private-firms.html
Also, from Guardian last month
However, Mark Davies, the centre's public assurance director, told the Guardian there was a "small risk" certain patients could be "re-identified" because insurers, pharmaceutical groups and other health sector companies had their own medical data that could be matched against the "pseudonymised" records. "You may be able to identify people if you had a lot of data. It depends on how people will use the data once they have it. But I think it is a small, theoretical risk," he said
www.theguardian.com/society/2014/jan/19/nhs-patient-data-available-companies-buy