Specifically Trading discussion > Services, Services Discussion. Those forums weren't active enough that it was needed. Most of the content in the new subforums is still on the front page of Trading discussion (albeit locked) supporting that trading wasn't overrun with these topics. It just makes finding new and relevant topics that much harder. What was the purpose of it? What does the addition of services add that marketplace, currency exchange, goods, ect. didn't offer. Seems there was already a place for most anything and services is redundant. Now instead of a few semi-active forums/subforums there's a bunch of dead subforums.
That wasn't a large board anyways, but it's a good preemptive split in my opinion. It's a candidate for explosive expansion.
Right now, Bitcoin Discussion is in danger of hyperactivity if it doesn't somehow get split again.
Here's my thread about splits that may be needed:
https://bitcointalk.org/index.php?topic=95077.