What is happening to the motion?
It will be printed on the Commons order paper tomorrow. Carswell is tabling it under "future business", which means that it is set down theoretically for debate that day (ie tomorrow), but that it is not expected to be debated that day. In other words, it is for debate on a "named day". That is not the same as an "early day motion" (EDM), which is a motion down for debate on an "early day" (in practice never). Carswell had been planning to table his motion as an EDM. But EDMs have no practical effect whatsoever.
Will it be debated?
Not necessarily. It is not unusual for backbench MPs to table motions for debate on a "named day".
Are you any the wiser? There was a time, about 30 years ago, when I spent hours sitting around in the House of Commons, trying to get to grips with this kind of stuff. Nowadays, I merely smile and pour myself another glass of pinot grigio.