1. A method for analyzing one or more policies applicable to a plurality of computing sites that host respective applications and process respective workloads in a distributed computing network, said method comprising: representing said distributed computing network, in its entirety, as a state transition model, wherein said state transition model is constructed in accordance with at least one model representing characteristics of said plurality of computing sites, where said at least one model includes at least one of: a site model, a workload model, a workload state model, a site state model, a policy model, an event model, or a cost model, and wherein said representing comprises: modeling, at a computing site, an availability of one or more associated resources as a state; modeling, at said computing site, one or more changes to an associated workload and one or more changes to said availability of said one or more associated resources as state transitions; and modeling one or more policies that dictate a manner in which said computing site shares resources with a second computing site as constraints on said state and on said state transitions; superimposing a queuing network model on said state transition model, wherein said superimposing said queuing network comprises: associating the state transition representing said one or more changes to an associated workload with a first probability that depends upon characteristics of said associated workload; associating the state transition representing said one or more changes to an availability of said one or more associated resources with a second probability that depends upon characteristics of failure and recovery of said one or more associated resources; associating said first probability and said second probability with respective policies; associating each of said respective policies with a third probability that depends upon at least one action to be taken in accordance with a respective policy; and deriving at least one steady state probability of at least one state of said distributed computing network in accordance with a queuing network analysis technique; and identifying an effect of said one or more policies on a performance of said distributed computing network in accordance with a solution to said queuing network model, wherein at least one of: the representing, the superimposing, or the identifying is performed using a processor.