This is an excellent update - really, the best possible outcome for a single day. But you're concerned, worried - because you know that it won't last forever, and you'll be right back here again.
The problem is that *consciously* he knows what he should and shouldn't be doing. He's just having a really hard time breaking the *habits* he's created. I know you know this, but it doesn't seem like he sits there and says to himself "I don't need to do any housework, she's going to take care of all of it". He's just goes on autopilot, and doesn't think about it. And once he's IN a game, it's almost impossible for him to actually extract himself.
I think pursuing the counselor is an excellent idea, but I'm going to give you one more, and there may be some disagreement on this one. TODAY, tonight, when you and he get home, I say grab him and plant a huge kiss on him, big enough to elicit a little shock. When he inevitably asks what that was for, tell him you really appreciated how he responded last night, how once he got started he jumped in on a number of different tasks without discussion. He made a real effort last night, and you don't want to let that go without some serious emotional positive reinforcement. I know you may feel, and rightly so, like you shouldn't have to positively reinforce what he OUGHT to be doing already, that you shouldn't have to hold his hand and say 'good job honey!' for things that are really just getting up to the bar, not surpassing it, but you have to remember that you're trying to *help him* break a habit. If he had an actual conscious attitude that he didn't need to do these things, I would have a completely different reaction. But that's not what it sounds like.
TODAY is a golden opportunity, because he's made a significant step in the right direction (I know, you're thinking, but I've seen this before and nada). TODAY you can bring it up and talk about it in perhaps the least combative zone, because he's made a good step and you can focus on that. Come at it with the positive, and then jump into "okay, that was awesome, and I know that you are just in a habit of getting yourself locked away on video games, and I know *we both* want to break that cycle, for our relationship. So what can we do to help that happen? Would it help if you put a post it note for yourself on the xbox that said "Please wait to play me til after the laundry!"? Or, what do *you* think would help you remember to make a little more balance?"
If he's participating in that conversation actively and non-combatively, and treating it like a problem to be solved, he'll start using those world famous man-stereotype fixer tendencies. And that's what you want - you want HIM to be fixing the problem, not for you to be mothering it away. YOU don't want to put the sticky note on the xbox, you want HIM to. You want HIM to acknowledge 'Dude, this is a bad habit, I KNOW I shouldn't be doing this, but I keep getting myself in this rut - how can I help myself get out?"
In some ways, it's no different than quitting smoking, or taking up a new diet, or starting a new gym regime. You have to want it, and you have to own it, and you have to find ways to 'trick' yourself into doing the new good habit instead of the old bad one.
BUT DON'T WAIT ON THIS! Start this interaction TODAY! Catch the efforts he made last night and solidify them with positive feelings, let him know that you see what he did, and you appreciate it. I am not saying in anyway that you're going to have to do a song and dance every time he just, you know, does what he's supposed to, but for right this moment, you're trying to turn the runaway horse around. And it does sound to me like he wants to also, just doesn't know how to keep it up yet when it's not in his immediate conscious thoughts.