I feel like there are still a lot of casting announcements to come for this film. While it may not be another 'AAA' star like Hardy or Smith there could still be some interesting actors circling this film.
The current working title for this production in Toronto is "Bravo 14" which likely reflects the 'Dirty Dozen' esque nature of the film.
http://www.omdc.on.ca/film_and_tv/Ontario_Film_Commission/in_production.htm
And while 'working titles' (or codenames) for productions aren't usually reflective of the actual (Blue Harvest, Oliver's Arrow etc, etc) film they do sometimes hint at what the production is. So while there may not be 14 members of this Suicide Squad I expect that there will be more than the 6 announced already.
I fully expect that the final Suicide Squad line up will include some DC 'Z-list' characters that will be cannon fodder just like
was in the Assault On Arkham animated film.
I also heard some speculation/rumor that the role Gosling was offered wasn't the Joker at all so it's possible that their might another major DC character still to be cast. I'm actually surprised that we haven't heard anything about Deathstroke yet. I know that he's a character that Warners are especially keen to do something with so it'll be interesting to see (providing that he isn't in this film) if he's kept for a potential Suicide Squad sequel or a film of his own.
Will Smith, Jared Leto, and Tom Hardy will all present similar problems. They don't seem the type to sign for multiple films, and if this is a hit Will Smith will be really expensive. It's possible we'll never see these characters again other than Joker. Who knows.
They have all signed multi picture deals. This was the reason given in the trades for Ryan Gosling passing on a roll. I wouldn't be surprised if their deals see them signing for multiple Suicide Squad films (should the first film warrant them financially) and potentially a spin off film (Deadshot and/or Rick Flagg) or appearance (Joker/Harley Quinn in Affleck's solo Batman film?) in another DC film.
Unlike Marvel WB won't have presented the actors with unreasonable multi film deals with next to no money. I'm not surprised in the slightest that Marvel have had trouble with casting recently. The terms of their deals only appeal to actors at the very start of their careers (Chris Helmsworth) or those on a downward slide (like Mark Ruffalo) because of the horrendous terms.
And talking of Marvel whatever happened to all that talk of Cumberbatch for Dr Strange? It's been a while since we heard anything about that.
DC is doing it
differently from everyone else.
Fixed that for you.
I've got a role for them...
I'm making a movie in my house...
*reads Escape Goat's script*
Wait, they are all plumbers coming round to fix your 'pipe'?
This thing needs a serious rewrite.