They are no more than political promises & we know what they're worth. The 3 main components of the Yes Coalition, FF, FG & LP, all promised to lower taxes for the rich in the 07 GE [they called the rest of us "economic illiterates"!]; look at what has happened since. Say no more.
FF & FG: Tweedledumb & Tweedledumber. 1 privatises TE, other will privatise ESB
By my reading, it's not especially that there will be active steps to make life difficult for us. It's more that if Lisbon fails, I reckon there will be a renewed move by core EU states to press ahead with a higher level of political, social and economic integration that they can agree to. The current Nice-level treaties will then be left to operate as a kind of super-European Economic Area. We may be happy with this arrangement, but in such a scenario we'd no longer be at the top table/part of the core/at the heart of Europe (choose your own description!).
If possible, better that all move forward a modest amount under Lisbon as a Union. But if this low level of compromise cannot be implemented, then alternatives have to be considered - the so-called two-speed Europe.
If Lisbon goes ahead, certain countries will be allowed to move ahead on certain policies, like common defence. But within the terms laid down by Lisbon. Any group of states moving outside Lisbon would be fundamentally calling the whole question of the Union into question.