Here's the scoop from SCOTUSblog:
Tuesday, March 26:
12-144 – Hollingsworth v. Perry – constitutionality of California's "Proposition 8" ban on same-sex marriage; also, question of standing to appeal
Wednesday, March 27:
12-307 — United States v. Windsor – constitutionality of Section 3 of the federal Defense of Marriage Act's benefits limited to married opposite-sex couples; also, question of standing for U.S. government and for House GOP leaders to appeal the case
Of course, with the current makeup of the Court, anything could happen in either case.
Stay tuned, with fingers crossed for equality.