USA today says they'll be available this week:
The Wi-Fi store was flawless in tests on the Touch, which Apple says will hit retailers later this week. Wi-Fi downloads, which will require a software update for iPhone owners, will also be available by then.
http://www.usatoday.com/tech/columnist/edwardbaig/2007-09-12-ipod-touch_N.htm
As with other things, I think this is a simple grammatical mistake (dangling participle and careless author). I think the "which Apple says" refers to the Wi-Fi store, but the USA Today author didn't realize that. Because they didn't, they assumed it's the Touch that will be available later this week, and hence the author added the part about "will hit retailers later this week." I would guess Apple said the Wi-Fi store would "be available" later this week, and the author just didn't realize it.
Another reason why I think this is probably the case is that I don't see Apple "leaking" to a simple news story that shipping of the Touches would happen 2-3 weeks before they said it'd be available otherwise ... I think there'd be a bigger announcement.
That being said, I'm hoping (well, trying not to get my hopes up, actually) that the previous two paragraphs are not true, and that the Touch will be shipping later this week. But I think it's unlikely.