Glad you liked the answer, but lets give a bit more detail on what was specifically gained for your case:
Feats:
4 Specific star pact feats were introduced later among them 3 potential general potential useful ones:
- Ulban's Flare: When you hit a creature with dire radiance and you have concealment or total concealment from that target, the target takes 2 extra damage and a -2 penalty to attack rolls until the end of your next turn. The extra damage increases to 4 at 11th level and to 6 at 21st level.
- Message of Doom Spurned: When you have a bonus from the Fate of the Void pact boon, you can apply it to all your defenses as an immediate interrupt when an enemy hits you. When you do, it lasts until the triggering attack is resolved, and then the bonus is spent.
- Veil of walking dreams: Whenever you deal Warlock's Curse damage to a target and do so with a warlock daily attack power, the target is dazed (save ends). If the power already subjects the target to a dazing effect that a save can end, the target is instead dazed and takes ongoing 5 psychic damage (save ends both).
1 multiclass feat with a divine class to deal radiant damage with eldritch blast and curse and
Paragon paths:
2 additional paragon paths were made for the specific star pact:
- Master of the Starry Night: No really clear theme, but quite useful and making better use of the apct boon
- Student of Caiphon: Focused on dealing radiant damage and supporting the group, but at a price
Of course also some more warlock and other paragon paths were also released
Powers:
There were binder powers released with a star pact rider, however, they require "Star Pact (Binder)", which is honestly a bit stupid, so you may also ignore that.
For each level of encounter powers (level 1, 3, 7 etc.) there were around 3 Powers with star pact rider released, 1 with the Arcane Power book and 2 in different dragon magazines. Some of these powers had charisma as main stat (Arcane power always, dragon magazine sometimes) and some had constitution as the main stat (dragon magazine), and all of them used int for a rider IF a secondary stat was used (but some are also useful without int).
Items
In adventure vault and adventure vault 2, there were also some implements (ok mainly 1 and 2 referencing the star pact) with specific uses for star pact warlocks introduced. in AV2 there was even a legendary set.
You can also find a bit more info in this guide where you can see how many "newer" powers etc. are mentioned for star pact:
Walk With Me in Hell: The Warlock's Guide