Some serious overreacting here. Fact is, that this was our first real match, we played away with 6 new players (3 new in defense!) against a team that is further in pre-season-preparation. It's no big deal to lose a game like this. I expected difficulties.
That being said, there are obviously some problems. Our defense was bad even in Serie B. And we didn't have the money to buy 2 quality CBs and a quality wingback. Don't forget we lost Cannavaro, Thuram and Zambrotta. It was impossible for us to replace them all. We have to get used to a not always stable defense for now, unfortunately.
I was no fan of signing both Tiago and Almiron either, since our wingers have their talent more in offense than defense and therefore we need a destroyer in central midfield to fill gaps and win the ball. We will see how this will work out in the future. It's too early to tell.
One thing is for sure, Juventus fans have to lower their expectations. The effects of the scandal are still there. We don't have one of the strongest teams in the world anymore and will suffer more. If we are 4th at the end of next season then we were successfull. If we are 6th we had a decent season. This is our region now. Get used to it for now.
This match against Newcastle was MADE to see those problems. You need a game like this to see where you stand and to see where there problems are. We saw them. Ranieri probably saw them, too. We will see how he reacts. It's too early to judge. We are still in try&error phase.