Wired is reporting that iTune Music Swap Just Won't Die, but they have some facts surprisingly wrong.
In April, Apple added a feature that let Mac users share tunes over a local area network, such as an office or a couple of Macs hooked up at home. This feature also permitted users to stream iTune music files. When some users published their addresses and began streaming iTunes music files over the Net, Apple responded by disabling the streaming aspect of the feature.
Leaving aside the typo, this paragraph is simply confused. The "share tunes over a LAN" feature is the same feature that permitted users to stream songs. Apple did not disable the streaming, they simply limited its scope to the same subnet, effectively disabling just the internet part of the streaming.
But the rest is true. 401ok does enable streaming across the internet again. Andromeda (available here from the Blogcritics site, by the way) does also permit streaming/sharing, but it isn't really a "hack" for iTunes or Mac OS X, but a full-featured application in its own right.
The best part of the article is the tip at the end. I still haven't updated to 4.0.1, even though I don't have another Mac to stream to, and now it looks like I've got a way to do it safely.