EA confirmed at their financial report this week that a new unspecified Dead Space game will be being released in the first quarter of 2013. With the amount of rumours circulating lately, I'd be more surprised if there wasn't a Dead Space game coming in the next 9-10 months or so, but that's just me.
And with release relatively close, it makes sense that EA are planning a big reveal at E3; it's obvious really. The Gaming Liberty has a source who has confirmed just that: Dead Space 3 WILL be making a showing at the conference. The only question they ask is will it be our first official look at the game or will it be confirmed beforehand? The difference is minimal; we already know the game is in development.
If nothing else, at least an official announcement will put to bed some of the rumours that have been on the net over the last few months. There's not a lot worse for a game than not managing to live up to that pre-announcement hype.