I just installed Fedora 15 beta with Gnome 3. I've done all the updates.
The networking applet asks for the wireless password every time it connects. I found this bug, which says that the issue is fixed in gnome-keyring-2.91.92-1.fc15. I have version 3.0.1-1.fc15, so this shouldn't be an issue.
Is there any other reason why the keyring wouldn't store the password?