Use a tool like Carbon copy cloner to clone the iMac to an external drive. Move the external to the MBpro and test booting the external drive. If everything checks out, Clone it from the external to the MBpro.
Edit: Link to Carbon Copy Cloner
I don't advise using a clone of a OS X boot drive/partition on another model of Mac.
only to the same model and year of Mac is what I recommend, too many things can go wrong, so prepare for it.
As long as you use a proper Reference release, which 10.7.3 is, it's a perfectly safe procedure. I've done it many times without issue. It's the principle that Netboot, Netinstall and Netrestore are based on.