Based on the rumors, it appears that Predators can now be taken as squadrons of 1-3 (like Whirlwinds, Stalkers, etc.) in the new Codex: Space Marines book.
Just like with Eldar tank squadrons, if you take 3 vehicles, it appears that you get a special bonus rule. In the case of the Predator Squadron, if you take three tanks, the rumor is that the entire unit gains Tank Hunter and Monster Hunter.
Based on this, imagine the following scenario:
-Squadron of 3 Ultramarine Predator Annihilators (i.e. 3 Lascannons each)
Use Tigurius to cast Prescience on the squadron, making all Lascannons Twin-Linked. Then target an enemy Monstrous Creature/Gargantuan Creature, like an Eldar Wraithknight, for example.
With 9 shots and TLed BS4, you should get an average of 8 hits. With S9 vs T8 and re-rolls to wound (from Monster Hunter), you get an average of 7-8 AP2 wounds. After the Wraithknight’s FNP, this unit inflicts an average of 4-5 unsaved wounds, meaning all you need is 1-2 more unsaved wounds and it is down for the count… and that is in a single shooting phase which, with the 48″ range on the Predators, can start turn 1.
Imagine the same scenario, but this time the Predators are targetting an enemy Land Raider. 9 shots, Twin-Linked, yields an average of 8 hits. With S9 vs AV14 and re-rolls (due to Tank Hunter), the squadron should inflict 4-5 glancing/penetrating hits, which is enough to smoke down the Land Raider (and any assault troop cargo it is carrying) in a single turn.
Finally, this squadron can be used as an improvised air defense unit, if required. Imagine the ame scenario, though this time the target is a zooming Storm Raven. 9 Snap Shots with re-rolls from Prescience yields an average of about 3 Lascannon hits. With S9 Tank Hunter vs AV12, the Predators inflict 2-3 glancing or penetrating hits which, with a little luck, is enough to destroy the flyer straight up (or at least force it to Jink, taking away its shooting power).
If these rumors pan out about Predator’s being able to squadron and get Tank Hunter/Monster Hunter USRs, I think they will become a very viable part of competitive Space Marine lists (and potentially Dark Angel lists too, if they get the same options).