From the Microsoft site I learned
that they combine collation and "ComparisonStyle" to a collation name.
I thought that case insensitivity had to be built into the collation, but apparently MS built case sensitivity in the database engine.
This would mean that Postgresql would need to build case (in)sensitivity into her engine as well.
Judging from the small amount of discussion on this subject, I am afraid this is not going to happen anytime soon. Alas, we will stay with SQL Server then (or maybe MySQL, but I will have to investigate).