No details have been released regarding the split probably because no one really expected it.
The two started dating back in 2007 after they costarred in Rendition together.
They never confirmed their relationship, but they didn't need to because in the summer of 2008 they took a vacation together in Paris and were photographed holding hands all over the romantic city.
This is really a shock. They didn't even seem to be on the rocks.
Just last month Reese gave an interview to In Style Magazine and it didn't seem like they were having any problems. She said, "We spend the weekends outside L.A, in Ojai, where I have a farmhouse. We have chickens and we grow cucumbers and tomatoes. I love it. It reminds me of where I grew up in Tennessee."
UPDATE: Thankfully, the reports of a breakup were just rumors. Their rep denies the split saying, "It's not true. They have not split."