Some people love it, some people hate it.
I almost always love anticipation. That feeling of something coming, approaching in a way that will change your world, even if only in some small way. I've even come to appreciate, to make myself aware of, that last moment before something arrives, because not every anticipated change is a good one. I say to myself, "This is the part when I don't know who the killer is," or "This is the part when I don't know what's in the case." (Of course, I still don't know what's in the case...thanks, Ronin)
In writing, there is often a need for anticipation to build throughout a story. In my experience, audiences have different tolerances for the length of an anticipatory period. Because there is such a thing as dragging something out too long.
Romance readers, it seems, have nearly-infinite patience as they wait for a pair of lovers to finally admit their feelings and act upon them. As Shakespeare said, "'Tis a consummation devoutly to be wished". The romantics in all of us have no problem with the phrase "hope springs eternal" either. As long as neither of you are dead yet (paranormal romance aside, of course), there is always another chance for love to work out.
Other story elements can't stand much anticipation before the reader gets frustrated or bored. Plot actions that we expect to move quickly shouldn't have too much lead-up before they actually do happen, no matter how long it takes in story-time for them to occur. Assassins strike quickly. No one wants to read about the two days a bit-part sniper sat shivering in the tree before taking a kill shot.
Main characters are the ones we're supposed to care about; things that affect their future, their lives, we want to anticipate (except when we enjoy sudden twists) to some degree. The smaller the character role, the less patience readers have for long, drawn-out plot results. Unless, of course, it's about love. Everyone knows characters have to fall in love by the end of the novel. And if they don't: sequel!