They need to get the right crew members and companies involved with a Looney Tunes production. For instance, compare "The Looney Tunes Show" with its' sister series "Scooby-Doo: Mystery Incorporated." The latter got a lot of WBA's A-list writers (even "Animaniacs" veterans like Paul Rugg), while the former relied on Improv writers from the Groundlings for the most part. Additionally, while TLTS typically had inferior animation by Rough Draft Korea (though several first-season episodes had great animation by Toon City), SD:MI had much better animation by Lotto Animation, Digital eMation and DongWoo A&E, three of WBA's main go-to overseas animation studios for non-Looney Tunes stuff. Music-wise, Robert J. Kral did a good job scoring SD:MI. But TLTS had Andy Sturmer providing the (rather sparse) music, and a lot of it was atonal and dissonant, not being very pleasant to listen to. So of course, SD:MI was the more superior show to TLTS.
I would get a lot of those A-list writers to do a Looney Tunes project, along with good designers instead of Jessica Borutski or whatever that are capable of being true to the classic cartoons and their animation, and have it animated by Toon City or Lotto Animation instead of just Rough Draft (that is, if they can't do it in-house.) Get a good composer that understands the Looney Tunes style to score it. And for sound design, get Robert Hargreaves and DigiPost.TV to do the post-production audio services. They understand how the classic Warner Bros. cartoons sound, and have access to practically the complete library of Treg Brown's classic sound effects (including ones not included on the Sound Ideas Warner Bros. Sound FX Library CD set, like the Tasmanian Devil spin, some of the other rocket and jet sounds, the original "trombone gobble," and the falling-down whistles.) Advantage Audio, on the other hand (who does "Wabbit"/"New Looney Tunes" and also worked on the second season of "The Looney Tunes Show" and its' companion movie "Rabbits Run") doesn't seem to know how a Looney Tunes cartoon should sound, except for the later Warner/Seven Arts cartoons (as evidenced by the repetitive Hanna-Barbera sound effects in "Wabbit.")
In fact, look how high-quality the Tom & Jerry direct-to-video movies often are (though the animation quality did take kind of a downward step when they switched from Yearim Productions to Digital eMation for the overseas animation services). They give Tom & Jerry the tip-top treatment but not Looney Tunes! If anything, they should make some more "Looney Tunes" direct-to-video movies, but not done as a single 70-minute story. Do it as several five-to-ten -minute segments that can be linked together by bridging material, all new of course, not unlike Disney's 1940s "package" animated features (particularly "Make Mine Music" and "Melody Time") or "Muppet Classic Theater." Maybe give each movie a theme, like do one that spoofs fairy tales the classic Looney Tunes shorts haven't parodied yet, or do one that spoofs classic or popular Warner Bros. movies (they could probably whip up nice ten-minute takes on "The Wizard of Oz" and "Willy Wonka and the Chocolate Factory" featuring the Looney Tunes characters.)
Just my two cents. Warner Bros. Animation really needs some sense knocked into them on how to do the Looney Tunes right.