Arrange to use the Far Cry 3 engine, go back toward the roots of the series, and a new GR could be both brilliant and not all that hard to create. Just the original GR's gameplay, with the bigger FC3-type maps and modern graphics would be killer. It's not like it was all that complex a game from a strategy perspective. That's one of the things that made it great: you had a simple set of tools (waypoints, cover arcs, ROE, a few special abilities), but with just that simple set, you had a lot of control and freedom. They could make controlling a soldier individually fairly action-oriented and first person (just like FC3 but with realistic weapons, damage and ballistics) so the twitch crowd would enjoy it, but still stay true to the roots that the thinking crowd likes.
They could pretty easily make a game that is genuinely superior to the original Ghost Recon games. Naturally, that won't happen because it makes too much sense, but I can always hope.