This may also be there to put pressure on the governments (local and federal).
I see three likely scenarios here. And in fact scenario 1 is probably a fact :
1) The cost of cleaning up the contamination at the site is causing friction in the negotiations. The fact is no one knows the costs. The low estimation is 40M, the upper I have heard is 175M. The mayor was on the radio several months back and was adamant the city is no way would be picking up that tab. You can bet that the development group wants nothing to do with it. The federal government could be balking (pure speculation on my part) as they are already giving up land worth 100+M. This could have a huge impact on the financials for the project, if they are getting a flat out no from the city (thats 100% certain) and the feds (no idea), this could be a move to apply pressure to them.
2) Financial aid. This is speculation, but based on what happened in Edmonton and Calgary. In Edmonton the total price tag was 613.7M, with the owner (Katz) writing a cheque for 25M and the city "covering" the rest. The city will recoup that over the 40 year lifetime in ticket surcharges, rent and tax levies. But the key was the owner only had to front 25M. Calgary wanted much the same deal, and it obviously was not going to work and hence they are in the process of determining the next steps (which sounds much like Melnyks speech). It would not surprise me if the same thing is playing out here in Ottawa. Melnyk could easily be looking for an Edmonton type deal, and being offered a Calgary type deal. In that case why would he not act much like the Calgary team and say they may have to move.
3) Melnyk may be pushing for the government to allow federal employees to accept tickets from suppliers. That will have a huge impact on what he can charge downtown, and will especially be critical to filling up luxury boxes. Given how poorly the government are doing at ethics at the moment, I cannot see that flying.
This whole speech at what is likely a critical juncture of negotiations (aren't they supposed to be up end of Jan?) may be more about applying pressure for negotiations.