I'm a Russian Jew so I have a genetic predisposition to always hope for the best but expect the worst. That said, I hope that this conflict can have minimal loss of life (for the Israelis) and will be over soon (once the goals are achieved). But there are some very dangerous wildcards that can turn this situation into a real clusterf*ck. The biggest wildcard in my mind is Egypt. It has 80 million Arabs, 70-80% of whom hate Jews with a passion and believe all the vile anti-semitic conspiracy theories that have ever reared their ugly head (like the discredited Protocols of the Elders of Zion). The timing of this conflict is such that I think the Egyptian government would prefer to sit this one out. They are still busy consolidating power and their economy is in shambles due to the revolution, that is hardly the time to seek adventures in a treasury depleting war. However, internal pressure from the Muslim Brotherhood (of which Hamas is a branch) and the even more extreme Salafists might force their hand. They have already recalled their Ambassador to Israel, chased away the entire Israeli diplomatic staff from their embassy in Cairo (either directly or through not being able to promise security) and now the Egyptian Prime Minister is planning on going to Gaza to show "solidarity". Discrete weapons sales (possibly of American make) and Egyptian "volunteers" bolstering Hamas' ranks could be coming down the pike. What happens if there is a ground invasion and there are Israeli vs. Egyptian clashes in Gaza? Nothing good, obviously. Israel is not prepared for heat coming from the Egyptians. So even though Egypt would rather have better timing, they could think that its better to go in now when the Israelis are also unprepared.
Then, of course, there is Hezbollah in Lebanon. I think Iran will want to hold back their Lebanese proxy from helping their Gazan proxy because they need to keep Hezbollah whole in case Israel attacks Iran. Also, Hezbollah is currently otherwise engaged in Syria so their front line strength is not what it could be. But what if the Iranians calculate that this might be a great excuse to spark a larger regional war. That they can have the anti-US and anti-Israel blowback without having to first be attacked by one or both of them? When bullets fly, strange things happen. Nobody thought millions would die because Austria-Hungary attacked Serbia either.
I just want to reiterate that I don't think either of these scenarios will happen. I think the timing of this is as good for the Israelis as possible. The Egyptian government is still consolidating power and Hezbollah is waiting to use its arsenal in the even of an attack of Iran. But it's also true that even the best timing might not be good enough. We'll see.
Whatever happens remember, Support Israel, Defeat Jihad.