Arnold Schwarzenegger and Maria Shriver -- It's NOT Over Yet

Arnold Schwarzenegger and Maria Shriver are in no rush to get divorced ... and there are 2 lines of speculation -- either they're so rich it doesn't matter, or they may actually get back together.

Several sources connected to the former couple tell TMZ ... neither Arnold nor Maria feel any urgency to get a judge to make the divorce official, even though all of the money and custody issues have been worked out. The reason, they say, is simple ... They're worth approximately $400 million -- which they agree they'll split down the middle -- so it's not like they need the divorce to buy a house.

Short story -- neither one of them is in a hurry to pull the trigger, because it will have NO IMPACT on their day-to-day lives.

And other sources say there's a different reason why they haven't gotten divorced -- they are not done with each other, and there's still a chance they'll get back together. Our sources say both Arnold and Maria have sent mixed messages to their friends and family -- at times saying they want the divorce, and other times talking about how they still feel love for their longtime partner.

One source says ... lately Maria is more amenable to divorce because she's hearing that Arnold has a girlfriend.

FYI, Arnold and Maria were together last weekend at their daughter Christina's graduation ... looking pretty happy.

Stay tuned ...