According to an official statement posted on their website - the White Stripes have split.
The statement said:
"The reasons is not due to artistic differences or lack of wanting to continue, nor any health issues as both Meg and Jack are feeling fine and in good health. It [the split] could be for a myriad of reasons, but mostly to preserve what is beautiful and special about the band and have it stay that way."
But perhaps the band themselves summed it up best by saying:
"The White Stripes do not belong to Meg and Jack anymore. The White Stripes belong to you now and you can do with it whatever you want. The beauty of art and music is that it can last forever if people want it to"