I always found it inappropriate for a large IT vendor like Sun to include such intrusive sponsoring.
Especially with a security sensitive thing like Java.
Anyway, I just learned that you can turn this off.. Not sure since when.
In the Java Options (Windows Control Panel -> Java) on the Advanced tab, scroll down to the bottom, and there you have it.
Suppress sponsor offers when installing or updating Java.
Quite hidden, and not easily found by exactly those average Joe Users who would actually install the Ask toolbar ...
But ... eh... thanks ?