Update: Disney has posted a correction to its earlier report, stating, "In D23′s News Briefs published April 15, 2014, we erroneously reported about the launch of the next chapter of Disney Infinity. This information was incorrect. More news about Disney Infinity will be shared on April 30, and we hope you will check back for that update."
Original story: Disney Infinity recently started hinting at Marvel characters, in a teaser that promised a "2.0 Edition." According to one official Disney source, it will be coming in August, just like the first game.
The official Disney fan club site D23 briefly had a blurb about the recent trailer, but let slip the August 2014 date that wasn't in the trailer. That portion of the text has since been removed, but Infinity Inquirer (via Polygon) caught a cached version. The blurb also says that it will include "familiar Marvel characters, objects, and vehicles."
An August release would make sense and has precedent, but it's certainly not set in stone. A Disney Infinity event is scheduled for April 30, at which time we'll probably get official confirmation of the release window along with more information on the Marvel inclusions.
An earlier report suggested that Disney is adding both Marvel and Star Wars characters to the mix. We don't know for sure if both franchises will make an appearance in 2.0. Even if they will, though, Disney may be holding back the Star Wars announcement for a later date.