I would take a backup of all the databases prior to the move in case something was to happen to the luns during the move.

I would also run select name, physical_name from sys.master_files and save it before detaching the databases because the drives/mount points might not come up the same on a different server and you will likely have to re-letter the drives.

Here is the process I follow:

1.Script out detach and attach statements

2.Run select name, physical_name from sys.master_files and save it for later

3.Run the detach script

4.Stop SQL server

5.Have the SAN admin offline the luns on the old machine

6.Have the SAN admin rezone the luns to the new machine

7.Have the SAN admin online the luns on the new machine

8.Re-letter the luns on the new machine

9.Run the attach script on the new machine