As an example, in the UK, we're going to get rid of analogue radio and go digital, which I would say is switching over to digital, though switching to would be OK.
I feel "switch to" is a temporary shifting from one point to another with the inherent option of reverting back while "switch over to" implies permanence of change.
As far as actual meaning goes, I can't really think of a difference either. My usage would be different for different scenarios though:
I'm going to switch over to BBC2 now for that programme I want to watch.
not
I'm going to switch to BBC2 now for that programme ...
I'm thinking of switching my gas and electricity provider.
not
I'm thinking of switching my gas and electricity provider over.
though I would say
I'm thinking of switching over to British Gas for my gas and electricity.