Right, well before my opinion on the original question, a Trey sequel?

Good news indeed.
I've been working on a fanfic story, had another one I was writing with a gentleman named Phate, (which has collpased by the wayside), as well as trying to finish my novel and get it sent off to my agent. Result? The collabaration has fizzled out, and the fanfic is getting updated less and less frequently as I'm on a deadline for the novel. Just being able to concentrate on one would have made my life so much easier. My advice, for what it's worth, stick with one until you get stuck, then go onto the next idea until ideas on the original start to flow again. There's no right or wrong way, but you'll end up with one of them that you're less enthusiastic about, and writing that one will become a chore rather than a pleasure. Plus, every story usually has a distinctive voice that you're writing with, doing different stories at the same time can lose the individuality, with the result that they can both sound the same. Fine if its the same type, but not so good if you're trying to do something different with it.