He's the only "holdout," in my opinion. Halvorsen is going to Tennessee. Drafting him was a crapshoot, and there simply isn't enough money left in the bonus pool to entice him.
I'm not sure what the deal is with Collins. All indications are that he's ready to sign. The Phillies can offer him a bit more than $165k. But maybe they're being "optimistic," and have decided to wait as long as possible on Halvorsen (kidding themselves, IMO, but still...), and have offered Collins just $125k - and Collins' advisors have suggested that he sit tight until the end of the month, until the Phils give up on Halvorsen and sweeten their offer to Collins.