a solo title
Team up with Nightwing
stay with the Outlaws
join a superteam
I would like to see Arsenal aka Roy Harper more in the Green Arrow book.
Daredevil is the best comic out right now.
I love Barry Allen but really miss Wally West.
The Punisher may be one of comics greatest characters.
I love what Snyder has done with Batman.
I really couldn't see a hypothetical solo selling very well. Green Arrow has the most recognisable name/brand with the TV series, Hawkeye over at Marvel is a critical hit and popular amongst fans and has the big bump courtesy of the Avengers. The only ones likely to pick up an Arsenal series would be fans of the character, and probably only really dedicated fans with the prices of today. However strongly those fans might feel, in actual numbers and potential profit, they fall well below what the executives/money-men care about.
Outlaws I can see him working with, but on his own? Not going to happen.
I think what we've learned about "side-kick" or "minor character" solo books over the years is that to get them started you really need to put them with a strong veteran writer (see Chuck Dixon on the Nightwing and Robin titles), or an eccentric writer in good standing (see Fraction on Hawkeye).
Arsenal could be a very strong book if the right writer is assigned to him.