Here is my stuff:
Wired Connection, directly to modem, no router, modem with newest firmware. Never had any problems with WoW or SC2 in terms of Bnet connection lost messages (I red here somewhere that if I might get the bnet chat connection loss message in WoW that this might be it as D3 requires this connection constantly whereas in WoW you could keep playing (Bluepost)).
I tried from 3 different connections (home internet, university and even wifi thether from my LTE phone). I have the 3007 error about every 30-45 minutes which is interesting because yesterday it was every 5-10 minutes.
I get booted to character selection and if I click resume, I get the error message that the game is waiting because not all party members are ready (playing singleplayer).
I got newest drivers for EVERYTHING on my system, cpu, video, ethernet, audio, all win7 updates are installed (genuine windows version).
I don't know if that helps but I looked from time to time at my ping and it was always around 200-400 ms with a green bar. I tired both on EU and US servers. No change.
Please fix ASAP as this makes the game pretty much unplayable.