For my money, the obvious way to do a Dick Grayson series is post-Batman.
Have him aged about 20, estranged from Bruce, for reasons we don't know. Despite this estrangement, Bruce has paid for him to attend university in a different city (I'm not familiar with tne Nightwing comics - presumably he's not in Gotham?) - Dick wants to pay for it himself, work through college, but on arrival, he finds, to his disgust, that 'an anonymous benefactor' has paid for his fees for the duration of his course. Although tempted to drop out on principle, after a phone conversation with Alfred (who we don't see - we just hear Dick's side of the conversation), he's persuaded to stay.
While Dick is unpacking his clothes for college, we see the Robin suit - he almost bins it, then at the last minute, crams it into some hiding place, presumably not to be seen again.
The show could also establish some new villains and old ones, of the type unlikely to appear in a Chris Nolan movie - your more fantastical ones. Probably to start off with, the traditional Bats gallery might be referenced and the show could intro some original ones. The pilot ep could introduce the main villain, some crime lord or gangster who Master Grayson ends up coming into conflict with - might there be some connection between him and the deaths of the Grayson family or between him and the estrangement between Batman and Robin? Whatever the reason, Dick ends up donning the Robin outfit and swings into action alone. However, by the end of the episode, he decides that he needs a new identity and decided to adopt the pseudonym Nightwing, for some reason which can doubtless be worked into the script. But while he's deliberating on a costume - he receives a package in the post - opens it up to find a new outfit, with a note, signed only 'B' - the rift may still be there, but is someone trying to mend it?
Dick could have a regular love interest - perhaps a rookie cop who's also studying on campus (on the short track to the DA's office, perhaps)? She's a little too old for him, but despite this is interested in this younger man who seems to have lived so much already.
I would have thought something like this is more along the lines of what CW wants. The hero is the right sort of age for their demographic (as oppose to the pre-pubescent Dick of circus days). They'd have a fixed setting, thus saving on location costs. Dick is a trained crimefighter, not a little acrobat. There would be more reason for him to come into contact with villains and the Batman rogues' gallery. I'm not saying I've reinvented the wheel here, but this sort of show could be a sort of Angel replacement, as oppose to Smallville's Clarky the Kryptonite Slayer. It's certainly much more likely to make a good Batman substitute than a pre-Batman Robin, which would at best provide enough material for a mini series.
