I have the same issue with my macbook pro with retina display. I have 2 macbook pros. I never would of thought that a bluetooth signal was interfering with both of them. I had a gateway wireless router that only had 2.4 Ghz 802.11 b/g, which is the same frequency of bluetooth. I know that bluetooth bounces from channel to channel, whereas wifi sticks to one constant channel (normally). I have reinstalled my mac twice, thinking that somehow my drivers were corrupted. This was false becuase everytime I reinstalled it did the same thing, Act fine for 5-10 minutes and randomly the internet connection would freeze up all together for 10-20 seconds. I have also tried contacting apple multiple times and they tried to do a smc and pram reset. They also tried to get rid of my chaches in my computer. It all seemed to be fine, and then when I got off the phone it would act us once more.
I have read numerous articles to try and fix the situation; one of them was to try change the location of the network and change the MTU size. No help. I called At&T (my internet provider) and got a new router and that did work for a while. But eventually acted up again. The router was still 2.4 GHz 802.11 b/g. I read this article and found out that my Magic Mouse might be causing the issue. Turns out to be true. Everytime I would browser the internet or browse the itunes store and it would freeze, i would immediatly turn the bluetooth off and what do you know, it works!!! This is a huge dissapointment in apple however. It seems to be only a macbook pro w/ retina display issue. My other macbook pro only acts up when i'm using my newer one (something is wrong with the bluetooth and wifi in the retina for the 2.4 ghz frequencies.
I just got a Airport express, and have not experienced this issue what so ever. This is due to the fact that it is a dual band wireless router. It supports 2.4Ghz and 5 Ghz both at 802.11 a/b/g/n which is a major improvement compared to what I had. I use the 5Ghz frequency and have no issues still.
This is still an issue however because if I want to go out and use anothers persons wifi, I can't control their frequency. So I will still have this issue. 😟😟