I can see how a lot of users have become emotionally attached to both the site's name and domain, and I'm definitely one of them.

But apart from Macworld having to pay the bills, there's another point that can be made in favor of moving the site and maybe, in a few years, after much consideration, renaming the whole thing eventually: Not only has this site outgrown the scope of Mac OS X years ago, there's also no guarantee Apple's desktop OS will be named "Mac OS X" forever. So the old domain was bound to become a nostalgic reference at some point, and the longer I think about it, the more I prefer it to have a more timeless name instead.

After all, I definitely want the former macosxhints.com to outlive that somewhat dated OS name. :)

(Full diclosure: I am friends with a certain MacOSXHints user named "robg", and I actually work with him, too. The thoughts I'm outlining above are not consciously affected by that, though.)

Correct. When the site started including iPod hints, it was a useful temporary home for them. When that extended to telephone usage, it was already getting wearisome. Of course, now we have tips for using the new portable picture frame. It's separation of those that's long overdue -- not changing the domain!

So. Follow through. Make the changes!

osx.hints.macworld.com
ios.hints.macworld.com
ipod.hints.macworld.com

Oh, and:

itsinthemanual.hints.macworld.com for your "select all" and "date & time" type hints.

That's not a bad idea.
hints.macworld could have everything and the others could be more focused.

macosx.hints.macworld.com would even "contain" the whole original name.