Excluding "religious worship services" when government opens up property for public access

May the government exclude "religious worship services" when opening up school space after hours to a range of private community groups? That's the question the Court has been asked to review in Bronx Household of Faith v. Bd. of Ed. of the City of New York. The court may decide Friday whether to hear the case (though it can always put off the decision for some weeks).

Two judges on a Second Circuit panel held that the government may indeed exclude such speech; one judge dissented. The petitioners are arguing that the court should decide whether the exclusion violates three matters:

1. the Free Speech Clause (on the grounds that it discriminates against the speech involved in religious worship services);
2. the Free Exercise Clause (on the grounds that it discriminates against religious practice);
3. the Establishment Clause (on the grounds that it discriminates among religions, and involves excessive entanglement, because of the need to determine which religious practices constitute "worship").

The split on the panel reflects how uncertain this area of the law remains.

What is the scope of Widmar v. Vincent (1981), the case that rejected a very similar exclusion in universities?

When does government property that's opened to public speech become in practice a "designated public forum" open to the public in general—so that content discrimination is generally forbidden in that forum? And when is it merely a "limited public forum" in which the content discrimination is allowed so long as it's reasonable and viewpoint-neutral? How do we tell when a content-based restriction is viewpoint-based and when it is viewpoint-neutral?

What Establishment Clause limits are there on the government's power to decide whether a particular activity is "worship" or whether it's just religious speech? What sorts of discrimination against religious practices are allowed under Locke v. Davey (2004), and what sorts violate the Free Exercise Clause?

I'd love to see the court resolve these questions; it will be interesting to see whether the court agrees to hear the case.