Believe it or not, there are still t-shirts being made out of Sly's Catch Phrase, "Ba-boom!".
There is a fan site which is frequently updated and has a large following, in addition to providing lots of info for longtime fans and new fans alike.
Non-Singing Voice: Not counting Michael Cade who played Sly the manager, or Diana Uribe as Lorena, all the cast members in the band sang and played their instruments except for Aaron Jackson who played Mark - his singing voice was provided by Zachary Throne. Jackson, however, did play his own instrument. Oddly enough, Jackson can actually sing in real life...
Rerun: Reruns are being aired on TV. And for Canadian fans of the show, they are aired on Much Music at 5:00am, 5:30am, and 5:00pm EST.
Reunion Show: The cast reunited and performed on Late Night With Jimmy Fallon in March 2010 to celebrate the show's 18-year anniversary, 13 years (up until that time) after it ended. Aaron Jackson and Diana Uribe — the Season 3 newbies who played Mark Winkle and Lorena Costa, respectively — were not present, however. You can watch it here; all credit goes to Jay Anthony Franke (a.k.a. Jake Sommers) for uploading it on his Youtube channel!
Revolving Door Casting: See Revolving Door Band on the Main page. But yes, the actors who were there since the beginning and have remained on the show until its finale were: Michael Cade (Sly), Kelly Packard (Tiffani), and William James Jones (Tony).