AFAIK, ETOPS only applies to twin-engined aircraft.
Per a new "Appendix K" to the FAA regulations, effective no later than Jan 1 2015, all new production Part 25 passenger aircraft will be subject to "ETOPS", regardless of the number of engines (never mind that it makes the ETOPS acronym meaningless). In something that I'm sure warms the hearts of you Freight drivers, the rules won't apply to Freighter aircraft with more than 2 engines
I haven't paid much attention to the new 3 engine ETOPS rules, but the 4 engine ETOPS rules have much more to do with how the other aircraft systems perform during an extended diversion (and the diversion need not be for an engine failure, although that is one of the scenarios that needs to be evaluated).
In-flight shutdown rate is not specified for 4 engine ETOPS.
Boeing is currently in the process of obtaining ETOPS for the 747-8i.