No, it wouldn't really make sense to try to serve Alfresco content through
Samba: Alfresco contains a Java component called JLAN which implements a
lot of Samba's file-server functionality, i.e it presents access to files through
CIFS, but behind this interface it is serving content straight out of the
Alfresco repository (not just from the filesystem).
That said, I don't see why this should cause any migration problems: most
basic CIFS operations on the filesystem will look pretty much the same to a
user whether through Samba or through Alfresco JLAN. You should even be
able to configure Alfresco to authenticate against the same back-end source
as you currently use with Samba, or (probably, I haven't tried it) directly
against Samba itself if you're using Samba as your PDC (but I'm not up to
date with the latest versions of Samba in this respect – perhaps somebody
else could comment). (Personally, I find that keeping user data in an LDAP
directory (OpenLDAP) and using Kerberos for authentication is the best
solution for using Alfresco with Windows clients.)
In short, the functionality that Samba would offer to Alfresco is already
integrated into Alfresco in the form of JLAN.