eLife has announced Research Advances, which allows authors to update their papers.
Here's an excerpt from the announcement:
The new article format, which we have named Research Advances, is for new results that build on previously published Research Articles or Short Reports in an important way. Authors will therefore be able to report progress in their research programs rapidly and efficiently when it is judged to be a substantial addition to the original work. These contributions might use a new technique or a different experimental design to generate results that strengthen, refine or even challenge the conclusions of the original research paper.
On a historical note, the University of Houston Libraries' e-journal The Public-Access Computer Systems Review began to offer authors the option of updating articles in 1995. For example, the 1995 "The Heinz Electronic Library Interactive Online System (HELIOS): Building a Digital Archive Using Imaging, OCR, and Natural Language Processing Technologies" and the 1998 "The Heinz Electronic Library Interactive Online System (HELIOS): An Update."