I am preparing an upgrade of our SS05/SP3 64-bit Standard Edition Server on a two node active-passive pair to the Enterprise Edition.

Is this all I need to do (aside from reapplying the Service Packs)
start /wait setup.exe ADDLOCAL=SQL_Engine INSTANCENAME=MSSQLSERVER UPGRADE=SQL_Engine SKUUPGRADE=1 /qb

Is there any preinstallation? there must be something.
How is the license upgraded to Enterprise?

I haven't found any good documentation on a procedure for this, other than the setup.exe command.