that's a local speed test. Blizzard is hosted on AT&T networks. The real question is, what kind of connection does your ISP have to AT&T.
edit: With TF2, you can see the server's IP address. Try to do ping <ip> and see what. If you see a low ping there, but you get a high ping in game, something more sinister is at work. Either something on your network is slowing down TF2 or your ISP is doing that.
tracert <ip> could also give you valuable data as it shows what your ping is to every hop between you and the server.
The route taken is very important
eg
http://www.pingtest.net/result/21479770.png
http://www.pingtest.net/result/21479786.png
You'll notice that German Town is 1/2 the distance that Chicago is, yet it gets a worse ping.