The final part of the meta puzzle is to discover the four names of Loki. The start of this final stage is given in the video awarded for completing the puzzles in Puzzle Box 4, and is the directory '/lokiv'.
It seems that the trail for each name starts with the hidden directory given at the end of the video each week that is awarded when all the puzzles have been solved.
The first week gave '/on_the_run', where Loki asked to be contacted (details on the Meta Puzzle page, which eventually led to the message about the 'murmuring rock project'. This has led solvers to believe that Loki's first name, or the name of the first Loki in the final video, is Lorelei or Loreley.
The second week gave '/collectionplate', where the number of white boxes that had been identified was recorded. Once all 36 of these had been found (nine per week) (details on the Collection Plate page, the page was replaced by a scrambled image. When reassembled, this image has been found to be the coat of arms of the Odessa Oblast (county). This has led solvers to believe that Loki's second name, or the name of the second Loki in the final video, is Odessa.
The third week gave '/more_answers', where the number of puzzles that had been solved was recorded. Once all 48 of these had been solved, the page was replaced by a word search of the solutions to all the puzzles (with an additional tetris-like drop down feature). When all the words are eliminated, one is left with the string '6B617261', which is the ASCII for 'kara'. This has led solvers to believe that Loki's third name, or the name of the third Loki in the final video, is Kara.
The fourth week gave '/roamingroaming', where an image of Loki with her glasses lowered was accompanied by a list of eight distances starting with '1. Mystery Spot CA', and the string 'TANLI'. The distances must be paired with the directions Loki gives in each video (in order of accessibility) when she lowers her glasses (where up = north, down = south, right = east and left = west) - the full sequence being right (hear the challenge video), up (box 1 real world clues video), right (box 1 complete video), down (box 2 complete video), left (box 3 complete video), down (box 4 real world clues video), left (box 4 complete video), down ('lokiv' directory video). Starting at the Mystery Spot near Santa Cruz in California and following the directions takes you to Atardecer en Donana, Spain, Bridgetown, Ireland, Warsaw, Poland, Tarnow, Poland, Dietzenbach, Germany, Bonnanaro, Italy, Blandinsville, Illinois and finally Hardee, Mississippi. The letters TANLI are an anagram of Latin, suggesting making an anagram and translating from Latin (or vice versa). Hardee is an anagram of 'hedera', which is Latin for Ivy. This has led solvers to believe that Loki's fourth name, or the name of the fourth Loki in the final video, is Ivy.
Note that the game makers first added 'CA' after 'Mystery Spot' and the text 'Even the smallest places have names' to the page after about 24 hours, and then added a link to a map of the area around Hardee with an X on Hardee (but no other text) after another 12 hours or so.
The solution therefore appears to be 'Lorelei Odessa Kara Ivy'.