Leonard Paul and Gordon Durity, 2 of the bigger names in game audio (as I understand it anyway), have recently started this online course: http://school.videogameaudio.com/
Think it's full for this year but you could apply for next year, and given their respective track records in the industry, I imagine it'd help a lot.
That aside, I'd say keep practicing your sound design skills on trailers etc (plenty to download at www.gametrailers.com), and start looking at the tools used by games developers. Wwise and FMOD are two to get you started, and both can be downloaded for free. There are also a bunch of tutorials on YouTube about the different things you can do with them.
And if you're on Twitter, follow @lostlab The guy is a seemingly endless fountain of game audio knowledge.
Links: www.audiokinetic.com for Wwise and www.fmod.org for FMOD.
EDIT: This one is good too, how Joshua Davidson at Gearbox got into games. Well worth a read: http://joshuadav.tumblr.com/post/8072664655/how-i-made-it-into-games-plus-a-few-things