Initially, I had thought it could be an episode dealing with bat ponies, which, as they are still highly mysterious and unknown in official MLP canon and I was highly interested in learning more, would be a welcome episode for me. But no.
Instead, the episode proved to be about vampire fruit bats, being "vampires" only in regards to the apples that grow in Sweet Apple Acres, and thus harmless to anyone (unless you're a juicy apple growing on a tree). But I had liked the fruit bats too the last time we saw them, and welcomed an episode on that too...even if I figured the plot probably wasn't going to be all that special.
And it was somewhat predictable. Applejack takes offense to the vampire fruit bats and wants them gone NOW, but Fluttershy, of course, wants to be more kind to them for reasonable reasons that the others don't see (like the bats help spread seeds for new apple trees to grow), and eventually they have to learn via Fluttershy that the bats were not as "bad" as they were first spun to be. You pick up on this plot line pretty quick, within the first five or so minutes of the episode, so you have a pretty good idea how this is going to end up and that's about it.
Kudos to the episode, then, because it presents a plot twist that I, I have to admit, did not see coming.