Create a marketplace...
Publish open free standards, requirements (like data storage location and big data analytics management) expectations etc...
Make some data sources publicly available (obviously not patient sensitive data), more along the lines of the bus tracking information, or police crime hotspot information, which allowed bored keen coders to knock together websites in a matter of days that out performed those paid through the nose for by the government.
Create an app store for health organisations to buy from (maybe link into apple/ google for some help with this bit and the code review/ reputation management aspects, which i imagine would be a massive factor in launching the system)
Sit back and watch as everyone from kiddie coders to multinationals compete to sell you their apps on a per user or whatever basis...
and then let the healthcare providers buy the ones that fit their requirements the best... it wouldn't work for all of the NHS IT problems, but it would for some, and would definitely shake things up at the top of the market...