Since this question actually came up twice already today, I figure I'll write it up. The question was whether it is permissible to eat matza balls this Shabbat.
Let's preface with an intro. The Palestinian Talmud (yes, the Palestinians have a Talmud, too) records the following statement: "R. Levi said, 'one who eats matza on erev Pesach is akin to one who has sex with his fiancee in his father-in-law's house.'" Indeed, quite the simile. Achad Ha'am (or perhaps Bialik - either way, a kofer who knew how to learn) allegedly commented on this: "I did both, and they were nothing alike."
Be that as it may, this law is codified by the Rambam (Laws of Chametz and Matza 6:12). However, the halakha only applies on the day before Pesach.
There are, however, various customs that extend the matza-free zone from one day to two weeks or even a month. So the question is whether eating matza balls tonight would violate the minhag.
I responded that since the main reason for the custom is so that the taste of matza is new at the Seder, one may eat it a few days earlier as long as it doesn't taste like plain old crispy delicious matza. Matza balls don't. I'd even say that one may use matza as soup croutons this Shabbat, as long as it's soaked through when you eat it.
In a nutshell:
1) It doesn't violate the letter because it's not erev Pesach.
2) It doesn't violate the spirit because the taste is altered.
Shabbat shalom and Chag kasher ve-same'ach