A really weak assumption is being paraded as a "rumor" concerning a possible casting addition to the Marvel Cinematic Universe. AssociatedPress/NewTimes (via CBM) says that Rudd was joking around with the Avengers cast and was told by an Oscar organizer that "You look like one". Apparently, this combined with a couple of tweets from Ant-Man writer/director Edgar Wright that focused on Rudd is sparking speculation.
I don't doubt that Paul Rudd is on some sort of radar but he's a really lousy lead actor in my opinion. His recent group of lukewarm comedies such as Dinner For Schmucks, I Love You Man, This Is 40 and Role Models doesn't inspire confidence in this being legit casting. However, Wright is known for odd casting choices hiring the ever wooden Brandon Routh (Superman Returns) for a supporting role in Scott Pilgrim.
On the other hand there are many other strong candidates to consider. One being Rafe Spall (Shaun of The Dead, Hot Fuzz) who has worked on many occasions with Wright and is prime to become another franchise actor being developed by Marvel (similar to Chris Hemsworth and now Chris Pratt). After a supporting role in Oscar winner Life of Pi and a small part in Prometheus. He also has I Give It A Year coming out soon which will hopefully give him more of an international awareness. Oscar nominated actor Bradley Cooper (Silver Linings Playbook, Place Beyond The Pines) and Joel Edgerton (Warrior, Zero Dark Thirty) have been previously linked to the film. Joel also being in the mix for Guardians of The Galaxy.
Considering the level of acting talent rumored to be linked, Rudd in my opinion would be better suited for a supporting role. I'm leaning towards Scott Lang rather than Hank Pym if it's an actual lead role. Lang ends up stealing the Ant-Man after being blackmailed and eventually partners with Pym. I wouldn't rule out Paul playing a villain either as Simon Pegg might end up being called up for Star Wars. Pegg had voiced a desire to play a baddie in Ant-Man. Even if recent casting of Park And Recs actor Chris Pratt for the Guardians of The Galaxy lead had Marvel hiring a comedian for an adventure film. Pratt had some decent Oscar connections with films Moneyball and Zero Dark Thirty to back up his abilities to handle other genres than comedy. Paul on the other hand isn't on that level and if anything would be comedic relief.
When it comes to the role of Janet (Wasp) I've finally come around to the fact that Alison Brie needs to be in that role. Alison was linked as a contender for Captain America: The Winter Soldier but was more likely being tested for another role in the MCU. A steady stream of actresses were linked for Sharon Carter but could have also been tested for multiple female leads such as Gamora for Guardians and Wasp (Anna Kendrick and Mary Elizabeth Winstead could also be strong contenders) for Ant-Man. The latter I think is where Brie fits in, as Janet is known for being as fast talking and as whitty if not more than Tony Stark. Her rapid-fire delivery on Community along with her dramatic side in Mad Men could see the actress in a similar spot as her Five-Year Engagement co-star Chris Pratt.
