Dismissing difficult decision-making as the price of power-sharing, the Sinn Féin deputy First Minister added that the Northern Ireland Executive was now "rock-solid".
"I actually saw some bookmaker somewhere a number of months ago was giving great odds for people about the collapse of the institutions prior to that (forthcoming Assembly) election - well, I'd say those odds have probably shortened considerably, because they now know that Peter Robinson and myself are absolutely committed to the maintenance of these institutions," Mr McGuinness said.
"And to get to an Assembly election without any collapse in the institutions in this term, under the tutelage of the DUP and Sinn Fein, I think in itself would be a fairly remarkable success."
Back in February, as the negotiations at Hillsborough Castle over the transfer of policing and justice powers from London to Belfast ran into a second week, at times the future of Northern Ireland's political institutions did seem in doubt.
But finally, after lengthy and intense negotiations, the British and Irish prime ministers were able to announce a major breakthrough.
Just months later, Alliance leader David Ford was installed as the new devolved Justice Minister.
And in recent days, it has emerged progress has been made on the future of the Maze Prison site and community relations.
"We're now in government - this is where difficult decisions have to be taken, this is where leadership has to be given," Mr McGuinness said.
"And, while people can record disappointments at different scenarios that don't develop to their liking , the fact is that these institutions are now rock-solid.
"They have, I think, the overwhelming support of the people of the North and they're supported by the Irish government and the British government, by the Obama administration, by the full weight of the European Union.
"I think the situation is rock-solid in relation to the institutions - but we can always do better."
'Work-in-progress'
Failure to secure local government reform or to set up the Education Skills Authority has caused concern among the Sinn Féin ranks and the deputy First Minister admitted that was disappointing.
"I think these are acute disappointments because of the financial implications that come with them - this could have saved us tens of millions of pounds," Mr McGuinness said.
"But that said, I think that there are other aspects of the Hillsborough Agreement that we're still working on and I think it's all a work-in-progress."
And Mr McGuinness does feel the DUP has a case to answer over those outstanding issues.
"I'm always very reluctant to talk about what is happening within other political parties, but we did make an agreement with the DUP on both the establishment of the Education Skills Authority and the Review of Public Administration and, for whatever reason, it hasn't been delivered.
"I think the DUP has to explain why that is the case and no doubt offers will be made on that front.
"But specifically when I make an agreement with someone, I carry it through. And I think it's very important that where you do make agreements with people, you do carry through and we have fulfilled every commitment we have made."
But after six months of power-sharing within a government with renewed devolved responsibilities, Mr McGuinness is hopeful for the future of Northern Ireland.
"I said at the beginning of this term of the Assembly that, even though Sinn Féin and the DUP would go into government together with the Ulster Unionists and there SDLP, that the first term would be rocky. And it has been rocky, there's no question of doubt about it - we have to be honest about that," he said.
"We know that there's any amount of critics out there who, at every opportunity, want to demean what has been happening - even though what has been happening has been historic by comparison to what happened previously.
"And I always also said at the beginning that the full test of the Assembly would be the next term because people were just getting to know each other - up until three years ago, neither Gerry Adams nor myself ever had a conversation with Ian Paisley or Peter Robinson about anything."
While the senior Sinn Féin member feels some of those within the DUP are "coming at this at a different speed", he added: "I think the DUP know that we have to move forward together and we have to move forward in a way that shows that these institutions can work, not just in this term of the Assembly but over the course of the next term."