It's being reported that the break-up of The Bella Twins was actually something that was done for the Total Divas show, as the producers of the show apparently pitched the idea to WWE officials.

Regarding how long the split will last, it's said that Brie and Nikki could actually be back together by the time Season 3 finishes up. Nothing is certain as of yet, but as for now, the plan is for the twins to eventually reunite.