An update from an article in the Wall Street Journal:
It appears that Mr. Stoudemire isn't Jewish under religious law. Mr. Stoudemire said his mother's links are solely from her study and appreciation of the Old Testament.
but, but, but...
While he doesn't consider himself religiously Jewish, he said he feels spiritually and culturally Jewish.
So yeah, Barely a Jew it is. Unless... well, there are plenty of mohels in Israel, right, Amar'e?