Ravrohan

For Claw Island, as Whispers, you get Ben Tennstrikes who you met in the Orders storyline or Gorr, whom all asura characters meet in the lvl 20-30 area. As Priory, you get brand new folks with dredge tech, or meeting up with the sylvari from "Act with Wisdom, but Act." As Vigil, you two new folks though.

In Orr, depending on your storyline options, you can meet up with:
*The sylvari from Act with Wisdom, but Act (ambush the Eye and later Vigil path to invade Cursed Shore)
*Gear Warband from norn blacked out storyline (Vigil path to invade Cursed Shore)
*Your racial sympathy option - always.
*Gorr - always, after taking out the Eye of Zhaitan
*Snarl and Galina from charr Iron legion storyline, if you attack the Mouth head-on.
*Ferghen from the Defend the Spirits norn storyline (If you joined the Priory to invade Cursed Shore)
*The two Priory folks from dredge tech that may have helped at Claw Island (Priory plan to invade Cursed Shore)
*Deborah, from human Dead Sister, joined the vigil and is present during the Vigil path to invade Cursed Shore
*Elli can be met in the sylvari storyline and seen again later during the Whispers' path to invade Cursed Shore (and another spot, I believe, earlier on).
*Scholar Inkblood who you save during Forging the Pact story step returns for Whispers' path to invade Cursed Shore.
*Agent Zott who helped retake Claw Island for all characters also rejoins for the Whispers' path to invade Cursed Shore.
*Havroun Grechin from norn Defend the Mists storyline returns for all players after invading the Cursed Shore.
*Priestess Rhie from lvl 20-30 human storyline returns if you visit the Cathedral of Silence
*The asura Statics college krewe return for Cathedral of Silence step too.
*Though not met before, Romke, the ancestor for norn Lost an Heirloom storyline appears if you don't visit Cathedral of Silence (well, his ghost - which is also seen in the standard Cursed Shore zone too).