I'm sorry to spoil @gary, but even if he is not directly affected by the CUxSP question, a lot of developers worldwide will be (in time). This is because the DBA can't change the application code when some random CU causes an un-wanted behaviour (because it wasn't tested enough to become a SP).

It will be the developer that will carry this burden. And the test-team fellows will feel this even more. So all the professional comunity will be affected at some level by this policy change, because it will affect not only SQL but all MS products.

Even if we don't test anything, installing 10 CUs over a year will cause more downtime than 1 single SP. I don't want to bring my servers down, no matter the reason. It makes me sad to see the server division getting messy because of end-user division changes.