Does each person on each team take a one of each jersey emblazened with team specs, etc? I understand that Cipo or Petacchi isn't going to prepare for a KOM jersey, but do all of the potential GC riders or sprinters or climbers bring two sets of jerseys just in case? There may be a simple answer that I'm overlooking, but just curious.

By two sets do you mean do they bring one green jersey with team logo in case they win it?

If so, no. The Tour will give them a green jersey with the team logos heat transfered on them.

So the Tour folks have the wherewithal to put those together in the right size with the right logos before they step to the podium? Impressive.

You'll notice that the yellow jersey (and I think it's the same for the other jerseys) that they put on while on the podium zips in the back. It's not the same jersey they'll wear the next day. As soon as the stage is finished someone behind the stage will quickly heat transfer a team logo onto the appropriate jersey. If it's needed that is. That night the team will be supplied with the real jersey.

I think the Giro still uses jerseys on the podium that riders have to pull over.

Yes.
One of the Tour vehicles is a van full of jerseys and team logos. for the podium (jersey with the zip at the back) they quickly cut out the team logo, heat press it onto yellow, green, KOM, white and send it up to the podium for the presentation.
Overnight, proper racing jerseys (zip on front) are issued to the teams at the hotel in the correct size for the rider.
All supplied by Nike, great publicity that they pay a lot of money for.

Gee, I wonder where we heard that before. Do people read all posts before responding?

I might save a copy and post whenever this comes up.