yes, here is how we gou about it
assuming you have sucessfully installed exchange server 2007 your enviorment below are steps
(however if you face issues during installation please post )
to move mailboxes:
you will you move-mailbox commandlet to move mailboxes to new server you can also use exchange management console
on the console you will see mailbox type .. user mailbox and legacy mailbox(exch 2003 ).. so after move is complete
there should be no legacy MBs
you aslo get events in application from exchange migration that mailboxes have been moved
and add new server on folder replicas to the exisiting public folder.
1. in exchange system manager drill down to folders
and under public folder right click each folder go to properties and in replication tab clic add
you will get your exch 2007 server name there.. select that
repeat for all folders .. even sub folders..
i would not confuse you with scripts as if now if you do not have a lot of folders
make sure sure to add public folder replica
for system folders as well
in the folders list.. right click public folders and drill down to "offline address book " and add replica and schedule +feebusy as well
after replication is complete you can uninstall exchange server 2003