In case you receive an error such as mount error(22): Invalid argument consider using the sec=ntlmssp,nounix,noserverino mount options.
The reason is that Samba has been replaced with SMBX in this release with the security tightened. You may also find that the ntlmssp scheme is only available in fairly recent, and not enterprise, versions of Linux.
Update: Red Hat 6.2's Release Notes state that, "Support for NTLMSSP authentication has been added to CIFS. In addition, CIFS now uses the kernel's crypto API."