Afraid that's going to happen a lot until OS X is (very) well established, and pre-OS X products are completely off the shelves.
Rule of thumb: if it doesn't say OS X on the box, it's not going to work natively. Software developers will very much want to make sure the big blue X is visible on the box, especially right now, when native apps are a bit scarce.
Unfortunately lots of people who see the words "OS 8 or greater" are going to get confused. In an ideal world someone would write a nice euphemism for "doesn't work on X". Then they'll will have to print out a gazillion stickers and paste them on all the pre-X software gathering dust at CompUSA.