The result itself is naturally a let down but it's totally insignificant.
What we saw was a United team that's ready for PL and Community Shield in only 9 days- whereas it's a Juve team that is just under preparation for the serieA which will start in a month. Manchester had already shown to be sensationally early on catching match fitness while routing Celtic 4-0 (in CL qualifiers as early as wednesday). This was no surprise, and less so when you consider the experimental status of the Juve lineup.
Our defence is not yet coordinated admittedly, and several players are quite clearly not in any shape at all. Here I'm referring especially to Trezeguet and Camoranesi, whereas Chimenti and Conte may just be that poor

. Legro wasn't too bad I think, but Thuram's expertise is noticeable in absentia, also because he covers more than his right side and thus leaves the central defenders in a better spot. Defensive organisation is something we have to work on surely. Ferrara, almost by default- seemed the better of our central defenders.
What is on the other hand encouraging is that Di Vaio shows much, much, much more promise right now than he did last year and more so, for a fan of Enzo's like me, Maresca has simply taken the same leadership attitude he had at Piacenza right back to Juve. This is a guy who seems to say "I don't care if you guys are all super stars, scudetto winners and CL finalists. Just give me the ball and I'll know what to do" and he fights like a lion as well. Personally- I think he is the best aquisition of the summer even if he won't see as much playing time as Legro or Miccoli for obvious reasons.
Last of all- some praise needed for Verón (marvellous game) and Nistelrooy who is so sharp you wonder why he's not constantly cutting himself. Phenomenal player, and quite simply the best area striker in the business hands down.
But worry not. When Lippi makes a starting 11 and players are in shape- we're ready to kick ass. Also United's although we have to respect that they're one of the great sides in Europe too.
I feel like adding Lippi's post game comment (tapped from BBC):
"When you play against a team of Manchester United's calibre, you know it is possible you might lose the game.
"But that doesn't mean you can just go out and play on your own.
"We are only 10 days into our pre-season programme and that might account for the 4-1 defeat because United passed the ball far quicker than we did.
"You can be a champion player but even great champions cannot play by themselves."
Lippi is very much right of course. It seemed as if some of our players tried to make up for the natural lack of coherence in the side by doing too much on their own. Both a natural reaction to team play being less than perfect at this stage, and because players wants to show themselves favourably as our squad is very deep right now. The result was us looking pedestrian in our build up, whereas United were very sharp and constructive on their passing. It's something to work on, and the players have a pre-season benchmark. It's not that bad at all.
Ciao.