Jesse McCartney is a voice actor for the Kingdom Hearts series; he's played Roxas for a few different games now. Earlier today, McCartney tweeted that he was "recording the next chapter" of the series, along with a picture of Roxas on a monitor, which you can see above. Unfortunately, the tweet and picture featuring the game have been removed; however, an earlier update confirmed McCartney is currently "behind the mic" working on something.
The question remains: what game in the Kingdom Hearts series is McCartney working on? The likely answer is it's the North American release of Kingdom Hearts 1.5 HD Remix, which features Final Mix, Chain of Memories, and 358/2 Days. Time will tell.