The latest D&D 4e excerpt, swarms, doesn’t bear much comment. It’s swarms, same as they were in 3e. They talk a lot about their “research” and “insights,” but pretty much a swarm is the same with a 4e statblock.
They do “clarify” that you can’t bull rush a swarm, which I must say has never come up for me, because you don’t need to write down rules for things that are blazingly obvious.
The one thing I don’t like is how fast swarms move. One of the ‘signature’ aspects of swarms in the movies is that they kinda mill about a lot and though an individual component is fast, the whole swarm doesn’t really move super fast, due to the need of staying together and just being kinda dumb. These swarms shoot straight at someone like an arrow, eat ’em, and shoot at the next guy like an arrow, which would be fine for some special swarm but not for all of them. 3/5.