Prorogation of a Parliament results in the termination of a session. Parliament then stands prorogued until the opening of the next session.
The principal effect of ending a session by prorogation is to terminate business. Members are released from their parliamentary duties until Parliament is next summoned. All unfinished business is dropped from or “dies” on the Order Paper and all committees lose their power to transact business, providing a fresh start for the next session. No committee can sit during a prorogation.  Bills which have not received Royal Assent before prorogation are “entirely terminated” and, in order to be proceeded with in the new session, must be reintroduced as if they had never existed. 
Since you need unanimous consent to re-introduce a bill, Harper's move means that, among other things, the revised Clean Air Act is a historical footnote. This reality begs the question, what was the point? Our elected representatives have wasted months, studying details, listening to witnesses, carefully crafting amendments and provisions, and in the end it means NOTHING.
You can't really blame the government for wanting to start fresh, eliminating any pesky matters that could cause future embarrasment, but that is really besides the point. MP's are sent to Ottawa to do the people's business. The notion of majority is primary, in any discussion of legislation. When you have a situation where the majority have come to agreement, it is just plain wrong that a simple move by the government can wash everything away.
There is clearly something amiss with a system that allows months of work to simply be erased, on the whim of what amounts to the minority. If prorogation of parliament has value, then it should be contingent on the majority of parliamentarians supporting the measure. Think of all the committee's still sifting through legislation- gone, forgotten, mirage. I don't think Canadians are particularly impressed by a system that can render work meaningless, wasting resources and time. Bill C-30, as it turns out, much ado about nothing.