The article Wish Upon a Star from Dragon 366 (still free at Download - 366_Dragon_Hi.pdf) has new feats and powers for the Star Pact Warlock.

7 Rabbit would love to have these available by the time he hits level 2.

It contains the following feats, all requiring the Warlock class, but not specifically Star Pact:

Heroic:
Sacrifice to Caiphon
Starfire Womb
Shadow's Eclipse

Paragon:
Twofold Pact (allows use of two Warlock pacts)
Bael Turath Born (Tiefling only)

Epic Tier:
Student of the Athaneum

It also includes new Warlock powers for all levels (again, available to all Warlocks, but most useful for Star Pact), a new paragon path Student of Caiphon (which does require Star Pact), and a new epic destiny Radiant One (which actually has no prerequisites except 21st level, but is thematically most appropriate for Star Pact warlocks).

Note that there were some revisions from the standalone version of the article, so be sure to look at the complete issue linked above. (The only one I can remember is that Twofold Pact was Tiefling only in that version.)