You want to know how long the idea of a Halo Movie has been around? Well, I do not know exactly when the idea started, but I will tell you this, that these concepts were created in 2008. Some time in that year, they were posted on LatinoReview.com, Microsoft sends them a letter, asking them to remove the concepts due to copyright infringement. But now the concept images are all over the web and its safe to show the images.
Kasra Farahani's drawings: