Bah
Apart from the obvious problems with successive govmts wanting to expand the scope of where they can get money from this mine of information, I've no personal objection to my suitably anonymised medical information being used by private organisations to further proper medical research on the proviso that the info isn't sold like a second hand car, but licensed, and the license terms include some nice (and enforceable) words about derivative medicines/treatments get given back to the NHS (or even the world in general) on very favourable terms (which would need some clever wording to ensure companies can't wriggle out of it, too) .
The govmts track record of making such deals is a bit poor, though, so I have no confidence such a deal would be brokered. It is more likely to be the companies making the govmt pay for the database, then give it to them for free with no strings attached - personal data and all.