User blog comment:Fearless Diva/Barry Allen and... Felicity?/@comment-24034641-20131106163750/@comment-4822026-20131107032543

Having a backdoor pilot doesn't mean for sure that he's getting his own show. (NCIS: Red never happened, for example, after it had its two-part introduction in NCIS: LA last season.)

Even if Flash did get its own show, that doesn't mean there couldn't be a crossover episode or two. The two shows would exist in the same universe after all.