It turns out that it's quite an easy road down which to travel given that it's a pre-existing Marvel comic story:
The short version of the story is that ex-con Scott Lang breaks into Hank Pym's lab and steals the Ant-Man gear, making it easier for him to get in and out of the numerous robberies he commits in order to help pay for the care of his sick daughter. Cross Technological Enterprises plays the part of the big organization against which Lang fights. In the end, Lang saves his daughter and tries to return the gear to Pym, who insists he keep it and use it to serve the law. Lang went on to take on the mantle of Ant-Man and has fought by the side of the Avengers and Fantastic Four over the years.
If this is the story Wright intends to bring to the screen, it is certainly an interesting way for us to be introduced to Hank Pym, a character with a long and storied history in the comics which pre-date the arrival of Lang. Pym was one of the original Avengers who squared off against Loki and was the creator of Avengers arch-nemesis, Ultron, though we know that, in the MCU, that origin will be changed. Marvel has shown very little regard for strictly following comic story lines but it would be a shame to have Pym reduced to a device to simply introduce Scott Lang. Pym does, however, have other superhero aliases he could assume that would allow for Marvel to have Lang and Pym actively a part of the MCU and it is hard to
fathom that Marvel would use Pym for just one film when he can be a part of some much larger stories.
What are your thoughts on having two Ant-Men in the MCU? Would you rather see Pym as Giant Man or Yellowjacket anyway?