Matt Graham at 2013-06-26 19:02:33:
It really comes down to the person. I work my best when I'm juggling projects. It gives me perspective and room to digest and process in the back of my mind. Then I revisit it.
A good way to handle it is to schedule around it. If you have a few ideas, set days to just work on them. Don't make it rigid, since creativity isn't a faucet, but at least you know you allotted time to work on your newer ideas while still keeping your older project in your head. Perhaps you'll have a hot streak and stick with one. Maybe you won't, but at least you won't feel victimized by SOS - You'll know specifically what other shiny is grabbing you.
I try to stick to one finished project before adding a new ball, but yes, that flexes so much it's hard to call it a rule.
I say, don't look at it as a syndrome or affliction. Rocker Josh Homme once said, "I don't suffer from ADD. I have OKHY - Okay, Hell Yeah."
It's the same thing, you are easily lured to your newest and greatest ideas. Don't consider it a crutch or obstacle. Work with it.
I can't think of any author who has said, directly to me or in an Introduction to a collection, that they zero in on one story or idea at a time. They write, shelve, revisit, shelve, write, repeat.
The key is to finish what you start. It takes discipline, but that feeling of having a finished draft, first or final, and sharing it with your editors of choice is more rewarding than the temporary buzz of adoration you get when you rapid fire your latest sparks of ideas off.