Bad news: furnace isn't 10 years old like I thought. It's more like 30 years old, but it looks clean and it works, so hopefully it'll croak while the house is under warranty, or it could run for a long time. Who knows? Who cares, it's not a deal-breaker.
Good news: roof isn't old and looks good, nothing leaks, the deck was constructed correctly, etc. The cracks in the foundation just need to be sealed up with caulk and painted.
Basically, everything that needs to be done falls under the "regular home maintenance/improvement" heading. The verdict from the inspector is "It's in very good shape." and "I wish all of these went this well."
[sigh] What a relief.