In the course of the Home Office's new policy to strengthen the British border and "raise the bar for foreign workers wishing to work in the United Kingdom", applicants for the Tier 1 categories 'General' and 'Post-Study Work' will have to face stricter requirements in the future.
However, the changes to the Tier 1 'General' will only apply to migrants who are applying for this category for the first time, or those who are applying to switch into this category from another.
The changes for applicants in the 'Post-Study Work' category mean that no points will be awarded for Postgraduate Diplomas or Postgraduate Certificates anymore, but only for Postgraduate Certificates in Education.
You can find both the new and the old guidelines if you click here. Please note that the new guidelines don't come into effect until 31 March 2009. So you should use the old ones for all applications before that very date.