The reason there is only a bare hint of slash is why I like it. I can even see CLex in the context of Smallville, but by the time they've grown up and been slugging it out for several seasons of the assorted animateds, I'm having trouble seeing there still being attraction or friendship.

That Wally is bi I'll believe; it's Batman I just can't see swinging that way, personally. (That, and I'm utterly in love with the idea of Batman/Wonderwoman. Not to mention that Wally's general immaturity - and Batman's usual proximity to a male orphan - just squicks me with the pedophilic possibilities. Don't wanna go there!)

Although now that someone has suggested Flash/Supergirl, I think they'd make an intensely cute couple. Not to mention an annoying one.