I haven't tried it with anything but 10.3.
But the answer isn't a simple yes or no.
For web browsing it seems to work great. But as soon as any heavy uploading activity occurs on the device, it either freezes the Mac or drops the network connection. The preference pane still claims the connection is there, but the device won't pass any packets. You have to unplug and plug the device back in for it to work. This uploading activity can be an email attachment, a file server upload, an ftp upload or a kdx/hotline upload. Any heavy uploading - seems like simple web requests or small emails work fine.
The DWL-122 page itself says it works with Jaguar, but I haven't tried it.
The most recent driver download claims to fix most of the problems I'm experiencing, but alas I still experience them even after upgrading to the new driver version (1.3.2)
How does the MacWireless USB adapter work? Anyone try it?
http://macwireless.com/html/products/11b/11bUSB.html
It's twice as much as the DWL-122.