queryBuilder.withAnalyzer(Analyzer)
queryBuilder.withEntityAnalyzer(Class<?>)
queryBuilder.basedOnEntityAnalyzer(Class<?>)
   .overridesForField(String field, Analyzer)
   .overridesForField(String field, Analyzer)
   .build() //sucky name

Perhaps rename the static factory methods to something like:

QueryBuilder.getQueryBuilder(Analyzer)
QueryBuilder.getQueryBuilder(Class<?>)

and QueryBuilder instances have overrideAnalyzerForField(String, Analyzer). Why do you need the build() method at the end?

if you do that, all of the sudden, a QB can change it's analyzer on the fly making it immutable.

Also the overridesForField methods would pollute the API when it's time to create a query.

One of the advantages of a fluent API in a strongly typed environment is that we can hide methods that are meaningless in a given context.

That been said, if the API ends up being pure Lucene and once we stabilize it, we can contribute it back even though I am not necessarily a huge fan of ASL.

Not it doesn't have to be either ASL or even hosted at Apache. I guess what I am suggesting is perhaps even a separate project - LuceneQueryBuilder or something - which plain-old-Lucene users could use as well. Doesn't matter where it's hosted or what the license is - as long as its ASL or LGPL :)