And in the meantime, I have three DH-inspired tribond threezers to share. These do all incorporate new info from DH, so beware of spoilers in the comments.
1. Harry...Neville...Ron
2. Voldemort...Snape...Buckbeak
3. Snape...Harry...Tonks
ETA: You all seem to have caught on to #1-2 right away, but #3 has stumped you. Hint:
Joie