Dragon #341 had Primus (3rd level) and Kas (4th).
Ashardalon (8th level, I think) in Dragon Magic.
Vanus, the Reviled One (6th) in the
Designing Your Own Vestige article.
And 3 psionic-related ones
here - Arete, the First Elan (4th), The Triad (6th), and Abysm, the Schismed (8th).
I imagine searching around the WotC messageboards would turn up some, but their balance might be questionable (but I'm sure most are just fine). That's what I recall off the top of my head. You should tell Paizo to publish some more in Dragon magazine. I know of at least 1 (and probably more) proposals that include them.
Either way, I would like to see more lower level vestiges since many of the new ones are all higher level.
I am currently playing a swordsage/binder but have been focusing more on the swordsage portion than the binding, so I don't have much experience yet. I'd love to play/NPC a pure binder someday to get a good feel for it. From what I have heard from others, they can be a bit rough to run until you can bind more than one vestige and/or gain the Expel Vestige feat. Before then, you are quite flexible between days, but during any given day, you are typically far more narrowly focused than other classes.
If nothing else, the flavor of the class is really fun. The other characters have learned to put up with my binder's "moodiness" from the various influences.