Okay so it won't be happening in The Bourne Legacy, at least that's what we can gather from Empire's interview with Jeremy Renner and producer Frank Marshall, but it looks like it's a good possibility in the future. In his own words Marshall lays out a few details to the possible future of the Bourne series.
You see there are several different programmes in the movie with different skill sets. All possibilities are open. My dream is that in the next one we see Matt and Jeremy team up.
Yes he said dream, but it's good to know the producers are on board, and furthermore that this movie is sure to open up the series to more storylines than before? Hopefully it's successful, as this seems like it could lead up to a team up of a whole lot of rogue agents creating the super-movie that I've always hoped I'd see in a James Bond movie. Be sure to pick up a copy of the magazine and get the full interview. I'm sure it'll make August 10th seem that much farther away.