Well, there's still (and always) baseball cards (and football, and basketball, and teenage heartthrobs, and Star Wars, etc etc etc). They're if not dimensionally then certainly spiritually the inheritors of the Carte-de-Visite tradition. So many CDVs were produced as an early form of celebrity trading card/collectible. God knows I've got enough of them in my meager little collection, from circus freaks in Barnum's American Museum to Civil War generals and social luminaries. Of course they were created and used for other purposes as well - I've got one by Mathew Brady that documents the Pleasant Valley Winery in the Finger Lakes area of New York. I'm not quite sure how you'd revive the tradition though, as a personal photographic medium. If you try to recapture enough of the historic characteristics, then you end up in re-enactment land and are just mimicking the original medium without saying anything new. Deviate far enough to say something new and quite possibly you've lost the reference and nobody will know/care why you're doing it.