If they go beyond 3 expansions that could work, but to have Cantha, the deep sea, and Bubbles all in one expansion and as the next expansion, it just feels more complete to me. There is something about that pattern that seems to fit with everything. You know how The LOTR and Hobbit movie series' have that Green/Red/Blue theme for each installment? That's similar to how I imagine the expansion trilogy of GW 2 so far. With HoT being the green one. PoF being the red one. And the UW expansion being the blue one. It also makes sense to finish off this human-central story with Cantha, and then go onto other areas of Tyria. Cantha is the most logical and beneficial place to go to for the next expansion and everything about Bubbles and the ocean areas can connect to Cantha. It's the perfect time to explore all of that and round out a GW 2 trilogy. Then I would have LW 5 and any possible further expansions or even a GW 3 deal with Primordus and Jormag. A Fire and Ice trilogy mixed with new lands, races, and a time period in the near-future.