I think he is worried about the quality of the maps rather than the quantity.
Arena.Net's way of providing content (everything is instanced) has a lot of potential, they could put a lot of scripted events into their maps.
From what I have seen in the first few missions, we can pick up and carry key items, use catapults, gain allies and even have to run (instead of the usual MMO style "kill everything 1by1") from a horde of Charr warriors.
However, keep in mind that every game is repetitive to some degree. That is why game genres exist. If I want to run around and shoot people I play an FPS, which for the most part should be "running around & shooting" and not hopping from one platform to the other, driving cars or looking for the 7 golden butterflies.
Guild Wars is very similar to a collectible card game, or a board game. Don't expect it to change your view on life, universe and everything else

just think of it as the lovechild of CounterStrike and CCGs.