There's been Tiny Titans. There's been the Li'l Justice League's appearance in Superman-Batman. Now there's THIS:
Yes, this is real, apparently. There's a comic book series in the works for Johnny DC, to be released at a not-too-future-but-as-yet-undetermined date.
Y'know, I don't normally go for the whole "Tiny-Toons-Muppet-Babies-Chibis" bit, but for some reason I find these so GOSHDARNED CUTE!! Awwwwww ... just look at li'l Batman. He makes me just wanna give him a big ol' hug and a cookie.