Apple censoring what other devices are allowed to exist outside their production-lines and what competing products customers are allowed to choose is.
Upcoming versions of both OS X and Windows take large steps in the same direction already. We all enjoyed a free software market for most of our lives. Now Android seems to be the only "personal computing" platform with a future.
And who knows when Samsung or Google are going to shut down that door on Android as well? It wouldn't hurt them, since neither consumers nor developers seem to care about independent software distribution anymore.
Government imposed restrictions on speech and/or commerce is something entirely different from plain old business decisions and it would be nice if we didn't conflate the two things by overloading the meaning of "censorship".
If you control software distribution on a plaform, you directly or indirectly control every information that customers of that platform receive. I think this covers censorship.
Of course iOS does not have a dominant position in the market yet, so censorship is limited by the customers choice to switch to another device. But as I explained above, the moment to speak against the control is now, as long as there are still alternatives left.
I think this "plain old business decision" is a political issue of great importance.
The problem with tossing all these things into the same etymological barrel is that you lose the ability to communicate effectively about their differences.
Government restrictions imposed by force are not the same thing as market realities created by private decisions.
Business decisions are not the same thing as public policy crafted via the political process.
It is true that business decisions can have public policy implications and vice versa. That doesn't make them the same thing though.
[1] probably not the best link, but probably close enough to the right answer http://wiki.answers.com/Q/What_percentage_of_Americans_own_a...