Yes he should. In fact I think he and Cuffe should resign from the Greens and join Labour, as Education and Environment spokespersons respectively, and bring an end to this whole sham with new elections. Incidentally, Paddy Power go 1-2 for a general election in 2009.
The Greens lust for power has seen them abandon most of their core policies (I'm thinking M3, Co-Location, Education promises, Incineration, Shannon, Lisbon, etc.) just so they could ban Stag hunting and lightbulbs, tax parking spaces and provide tax relief for bicycles . . no wait, they didn't quite manage any of that, but they did manage to divide their party.
The Greens went into government with the belief that they would be in government, holding the balance of power, for the next 20 years. Recent opinion pools have shaken that belief as it seems that they are surplus to future requirements. Gormley and Ryan have nailed their colours to the mast of FF Titanic but Cuffe and Gogarty can and should jump ship.