If thinking of PLO Chieftain Abbas in going to ICC is to buy time till Israeli elections, then one can see some merit in that. This is because after joining ICC, PLO will have to wait in any case for around 3 months to lodge a case and by then Israeli elections will be done (voting on March 17). Having the option of going to ICC strengthens PLO in negotiating with Israel. But that only works if Israel is ready for any kind of engagement.
By going to ICC, first of all PLO has made Israeli Hawk's argument stronger in the thick of an Israeli election. PLO did not show any political dexterity of strengthening hands of moderate and centrist forces in Israeli election, players like Tzipi Livni and Isaac Herzog. Seems like with Hamas on ascend, PLO is interested in taking head on with most Conservative forces of Israeli politics. What all that means is any ruling coalition after Israeli elections would have much less room to negotiate with PLO. There can be differences based on who becomes Israeli PM. If Tzipi Livni or Herzog were to become PM, it is possible that new Jewish settlements would not take place. But with Bibi at the helm it is impossible to imagine how he would stop settlements. Continued settlements is 'the rent' which a Likud coalition has to pay to Ultra-Conservatives in order to stay in the power. Nevertheless jumping the gun and going to ICC is fitting with the pattern of PLO - the same way it sabotaged last year Sec. Kerry's peace proposals. All this means either PLO does not think stopping of settlements is of any use (which in minds of any rational observer is the single most important condition to restart peace negotiations on credible footing) or PLO simply does not understand how to serve its own interests.
This is because, going to ICC is risky. First of all, it is not given that ICC would take PLO's complaints. Like USA, China and India; Israel is not a ratified member of ICC. American Congress is bound to stop all aid money to PLO when it lodges a complaint with ICC and Israel can stop all transfer of tax collection to PLO. Only European monies will continue to PLO. But the Europe which is barely coping with Russian Dictator Putin (come Spring of 2015 Germany will be embroiled in an intense debate of continuing sanctions on Russia or not), dealing with hiss fits of Greece, looming danger of Brexit and barely battling it's own economic stagnation is hardly in any great position to support PLO in the first half of 2015. There will be some noise in France and UK might pass some symbolic measures to garner Muslim votes in May elections; but thereafter it is harder to see how Europe will be the real back stop for PLO. From media strategy point of view, European political landscape will be consumed by so many internal challenges, it is hard to believe Israel-Palestinian issue would register more than existing noise levels.
Lack of political maturity and better understanding between Hamas and Fatah are stalling Gaza while hellish life continues there. Once money stops coming to PLO upon opening a litigation against Israel at ICC; all those warm stories about how a competent West Bank minister improved lives of Palestinians will be gone and West Bank will join Gaza in misery.
The real shocker to Palestinian people will come when Israel will retaliate PLO at ICC by filling cases against Hamas and all terrorist activities by various PLO folks. If any of those claims stick, there should be buyer's remorse in PLO for going to ICC. Equally, if ICC decides that it better stay away from this political quagmire, Palestinian's will realize uselessness of going to ICC.
When UNSC declined the statehood request, PLO Chieftain is right to ask "where are we to go"? But the answer this question has - uniting all factions of Palestinian people and presenting a peaceful, credible negotiation partner to Israel - PLO does not seem ready to accept. History of Palestine - Israel conflict has been such that Jewish state winning land, then giving back part of the land in the hope of peace while Palestine sticking to a perfect solution and in the process losing everything. That is what Yasser Arafat did and that is what Abu Mazen doing today. He is worried about his own irrelevance among Palestinian people - it is unlikely that it will be addressed by superficial actions like going to ICC.
In 2015, the global politics is unlikely to be any more receptive to predicament of Palestinian people. Obama Administration's priorities in Middle-East are clear - securing Iraq by defeating ISIS, putting conditions in place to eradicate both ISIS and Bashar Assad in Syria and clinching a deal with Iran. There will be zero interest as well as need for Obama Administration to invest in Israel-Palestine conflict. In a sense, it will be on auto-pilot and Congress will do all the hard work. With Europe pre-occupied and American politics firmly rolling towards 2016 election (which will invariably retain / strengthen Conservative pro-Jewish bias of American polity); Palestinian cause would reach a dead end pretty soon.
Another intifada or another battle is par for the course in these affairs. So long as IDF avoids mass killings of Palestinian innocents to remain below radar of global 'outrage industry', Israel's mastery in "periodic grass mowing" will come handy. So the real interest of coming Israeli election will be how that election sets the course for a "unilateral solution" to this problem. Going to ICC now or engaging another mindless intifada, when those are the responses of PLO; Israel has to live with "no credible partner" and chart her own course in Middle-East. With President Obama occupying the Oval Office, Palestine had had an opportunity to work out something. That window is closing very fast. Republican President in 2016 is quite possible and even if Democrats win, it will be Hillary who will be more hawkish than Obama in these matters. All in all, we might be looking at early signs of Palestinian resistance getting folded to History books like many other moral, but inept resistance movements.
 - As a recent ICC case shows, if the court finds that a national court is able to prosecute alleged criminals, it would not take such cases. So long as Israel can show it has prosecuted excesses by IDF, it may be able to claim non-admissibility of Palestinian cases against IDF. On the other hand in absence of Palestine lacking any prosecution of terrorists attack by Hamas, PLO could be on a weaker wicket!
 - One can argue that to cut down Hamas to a size, Abbas picked the gauntlet of going to ICC in full knowledge...no idea if that is the kind of sophistication Abu Mazen is trying here.