Not Stable at all.
The fact of the matter is that the militias were using the US troops as an excuse to perform acts of terrorism and have targeted Iraqi civilians instead on so many occasions. Therefore, the departure of the US troops didn't even reduce those acts, in fact, it has increased them simply for the lack of a strong military presence in the country. No, the Iraqi army does not qualify as "strong military presence."
I know that everyone, including the Iraqi government/people, was demanding the US to withdraw their troops from the country, and I have to say that it was a necessary move for Iraq to finally go on its own and try to establish peace. But reality is something different. The Iraqi government is very inadequate, and the number one reason for that is that its very composition is based on the concept of Iraq being a cake that everyone has to get a piece of!
Consequently, no matter what, the Ministry of Foreign Affairs, for example, is always going to be managed by a Kurdish minister. The Ministry of Defense is always going to be handled by shiites, and so on. This means that the Ministry of Health is going to be handled by someone who belongs to group X regardless of the fact that a certain person from group Y is really the right man for the job! This obviously results in people not knowing what they're doing, and performance across the board suffers.
Furthermore, sharing the "cake" in that matter means less cooperation between different ministries and departments based on their leaderships' loyalties. And of course, there is always the usual grudge between two people that halts the workings of two or more government entities. After all, you don't see everyday a prime minister going after the vice president for accusations of terrorism, with the latter getting protection from the president, then fleeing the country with the president's help ... oh, and did I mention the terrorism outbreak that accompanied that? Yeah, people died ... because the prime minister doesn't like the vice president .... this is one government we're talking about!
So, with that in mind, I think it is impossible for Iraq to become stable anytime soon. We need stronger leadership and unified efforts. We need everyone's loyalty in one place, that's Iraq, not religion (read: Shiite vs Sunna), not nationality (read: Arabs vs Kurds), and certainly not other countries (read: Iran).More questions on War in Iraq (2003-2011):