call me crazy but I've been considering swapping my 5Diii for a 6D/7D pair... The problem is I love love love my 5Diii. it's really the best single camera body I've every used. But I'd like a cropper and I'd like wifi so the swap makes sense in that regard. But it's tough.
Wait for the 7D2 which will arrive in 2014 and will probably have WiFi. This way you can keep your 5D3. Another option is buying a CamRanger which will add WiFi to your 5D3 (but in a more advanced way than the EOS Remote app).