Last night, we playtested some DC Adventures encounters for Owlcon. Not mine, some from another guy in the group who's running a "Crisis of Infinite Batman" session. It was good fun and helped me see some rules I need to brush up on before my game rolls around.
The session did bring up one sad truth of an established gaming group: The need for buy-in. About half our group are hard-core comics nerds. The other half like superheroes, but they're not walking encyclopedias of nerditude. As a result, only about half of the stuff the GM threw at us (like King Solomon Grundy and the Kryptonite/Venom Joker from "Elseworld's Finest") had the desired impact on the audience. And that's unfortunate.
I've experienced this myself in the past when I tried to run a game on the heels of our very successful "Fair City" Champions campaign. Unfortunately, the player mix in that game was similarly half and half and I didn't handle or prepare well for the blank stares I got from describing something as "A Thor's Hammer pendant designed by Jack Kirby."
All of which reminds me that in my upcoming Justice League Unlimited game, I can't assume the players are all going to be fans of the animated series or understand the differences between the show's Hawkgirl and the comic version(s) of the same character. Or even know who the characters are at all, for that matter.
In short, I need to to a lot more writing between now and then, as well as work up some spiffy visuals.