The Governments stance has been softening for a while now - seldom will you see those caught in possession get anything more than a slapped wrist.
Fact of the matter is that
marijuana is less damaging than say tobacco or alcohol. Those have been freely available for years, and account for a huge number of deaths globally, so you've got to wonder what grounds they have for not legalising it completely.
That said, I do applaud their move towards making it available for medicinal use, as I know that it is far preferable to strong painkillers.