Shias were literally oppressed under Saddam. They were basically the second-class citizens. And they were more than 60% of the population. Maliki is not even close to such level. He indeed $#@!ed up though when he single-handedly, instructed by Iran, put an end to all hopes of a power-sharing government in Iraq. Sunnis are of course not happy (and Saudi's been playing their dirty role in stirring the pot) but in no way can you even compare the systematic discrimination against Shias (and Kurds among other minorities) to what's currently going on in Iraq.
That's what I was hinting at, his political path and decisions is costing immense blood which is resulting into civil war. To me it looks like he is more interested in seeking revenge against his political and sectarian rivals than build a country. Just couple of days ago I was dining with some friends, two of them were Iraqi Shi'ites (just like everyone on the table including myself

) and they thought Maliki could have prevented so much blood if he had taken better decisions or at least open door to his political rivals to reduce the damage that already happen.
I think Shi'aa fear the return of the Sunni rule, and Sunni still feel sorrow for not being in power since Saddam and both are climbing back and this is why I personally think Maliki is a criminal because he hasn't resigned when his political decisions have costed thousands of life in the last few months.
I agree Saudi never had a clean role either and their relation with Iran has been fvcked up ever since they have become the two Gulf super-powers and the only way to ease the regional tensions if both sit down for talks.. But if we compare both countries influence in the region then it's easier to side with Saudi political path than Iranian (As a Lebanese at least) and not that I'm impressed or fond of Saudi but because there's no other option.
From my experience I can say that the Iranian influence is a lot more dangerous than Saudi, Hezbollah being the best example whereas you have the Saudi's backing up and consolidate with Rafik Hariri before he was assassinated and now with his son Saad Hariri (An open mind young politician who's got Shi'ites as much as Sunnits in his party). That's just an example anyway.
Iran is not the source of any unrest in the region, believe it or not. Iran's regime is ideologically divorced from those groups. Da'ash/Nasra making an attempt on Iran? Man, we are talking about a couple of terrorist groups who are born in politically unstable environments preferably when religion is an inseparable part of the society and the people's lives and are relevant as long as they bomb themselves here and there. Iran is politically stable and has a powerful army (Sepah). Those groups are certainly supported financially and ideologically by some powers but both logic and history say it's Saudi and their friends.
Do you think Iran care if their ally share the same ideologically view/beliefs so long they are benefiting from them?
History indeed say it's Saudi behind these groups we mentioned but history also say that these same groups were used by the Syrian regime as tools whenever they wanted to negotiate something in Lebanon as well as used by the Iranians at some point in Iraq. Personally, I think too many countries are involved in these terrorist groups including both Saudi and Iran, them terrorist groups are like any product in the market, whoever pays more gets the services no matter what the agenda is.