Funny, I've just recently been noticing the same thing. And this is my 5th year in Kunming. I used to only have to use the VPN occasionally to get to some very specific sites but lately I have to run the VPN almost all the time just to go to sites that normally aren't blocked.
Still, I am assuming that it is actual blocking and not a slowdown or hop count problem. Sure glad I've got a good VPN but let's hope this is just temporary.
Like someone else mentioned, I even today had to use it to get to GoKunming site.