I have a feeling I might be a little younger than previous commenters. I look over that first list, and none of that really upsets me or worries me. I can't think of any of my peers that worry heavily over any of those, either.
The Post Office: I worry about this, but mostly because my dad's a letter carrier. He seems to think despite financial trouble, rumors of the post office's demise are greatly exaggerated. I don't think many of us in the 18-30 range are worried about it, though. Mail is still important, it'll get there somehow. If the post office fails, that's one of those times The Glorious Hand of the Free Market will step in, right? Maybe it'll cost $20 to mail a birthday card, but that's what e-mail and Facebook is for.
The Check: I have a checkbook. It's the the same one I got when I was 18 (almost 8 years ago). I've used maybe a dozen checks in that time. I think debit is faster and easier for most of us. Personally I'm making an effort to keep cash on me, because I have trouble keeping track of money no matter what medium. Actually being able to count what I have in my wallet helps. But I can pay with my debit card almost anywhere, and if I can't, there's always an ATM nearby.
The newspaper: The same content is available online, and not just through the paper's website. You have access to your choice of news network websites, blogs, anything you want. It's possible some places might start charging for services, but typically people will begin using another site. There may come a day when nothing on the net is free, but I know a lot of people who are dedicated to fighting that tooth and nail. My parents have a bi-weekly subscription to the paper, and I usually end up at least thumbing through the Sunday edition, in addition to my online reading.
The book: I am one of those people who likes the tactile experience of books. I like how they look, I like holding them, and I especially love Old Book Smell. I know a few people who use a Nook or Kindle to do most of their reading, but you know what? They still buy books.
Land lines: Our DSL works through our landline in a process I don't even pretend to understand. However, I haven't used a landline to place a phone call in who knows how long. I wouldn't cry if I didn't have one, though I understand it's a necessity for others.
Music: MP3s are so much easier. I think if we were using records, where the album art was still a major part of the experience, I'd be more upset. I do still buy CDs to support artists I really love, or if one of my favorites puts out a special edition. Otherwise it's all digital. If I'm listening to music I'm either on the computer or in the car, or occasionally out in the barn. The computers stores all my music, the CD player even in my old truck reads MP3 files, and I have an old set of computer speakers and a cheap MP3 player out in the barn. It's a lot easier than hauling CDs back and forth.
Also, there is good, innovative music out there. You just have to look for it since it rarely hits the airwaves.
TV: I like having mine on as background noise, but I have started watching a few things online. It's nice to sit down when I have some free time and watch three shows in the time it would have taken to see one, or catch up on a whole season of something on a lazy day.
Things: You always have the option to have things. Even if people stop selling them. You can get books for cheap at thrift stores and yard sales. You can burn you own CDs. You can print your own pictures. If you want 'things', you can still have them.
Privacy: I think this is a more real concern, but not as it's outlined in this oft-forwarded e-mail.