I have no idea how to close and mirror threads -- I'm just an iPod user, like you. I've been following this discussion group because I've been wary of iTunes 10.5, and have learned a lot.
I took a look at the thread you indicated. I tend to use Occam's razor on these things: the simplest answer is often the correct one. If there was a major design flaw, Apple wouldn't have sold so many classics. Therefore, whatever this problem is, it is likely at the noise level in terms of overall sales (like, say, the Toyota acceleration problems :-)). That doesn't mean it doesn't exist, mind you.
Now, I will share one idea that occurred to me. I'm a stickler for getting songs to play right on my iPod. I've had a few times where a song would act up, yet play perfectly find in iTunes. When that happened, I hypothesized that the problem was the codec (decoder) used on the iPod. Often I've been able to take the song and convert it to mp3 or aac (i.e., the opposite of what it was), redownload it to the iPod, and it plays fine. So my theory might be that there's something common in this music that is triggering a bug in the iPod classic software. This likely wouldn't show up on the iOS devices, because they are running different software. Will Apple fix it? I doubt it--I don't think we're going to see any updates to the Classic software... the classic line will limp along until they get a large storage iOS device.
That's about all I can suggest. I, too, don't want my Classic to fail. I have nearly 28,000 songs on it.