Using your focus target has been the topic of much discussion in the past few days here at WoW Insider. Mike mentioned his interest in using macros to utilize the focus functionality built into the default UI. Tekkub's Control Freak was profiled, which basically automates the process of using crowd control abilities through the use of macros.
WoW Insider reader Aaron provided a very good macro for those of you wanting to make use of your focus target to maintain Polymorph on a focus target.
Here's the macro, ready to be copied and pasted into your macro interface:
/focus [target=focus,noexists]; [target=focus,dead]
/cast [target=focus,exists,harm] Polymorph; Polymorph
Come on back after the break for an explanation of what this macro does.