I like the idea for a Cranberry tart.
But, if you're still thinking of something citrus-y, to me, a classic lobster dinner calls for a classic dessert, like Lemon Meringue Pie.
Maureen (kima) posted a recipe for lemon meringue pie recently that sounds great. I'm thinking of trying it soon. You can find it on this thread
"We reject as false the choice between our safety and our ideals. Our founding fathers, faced with perils we can scarcely imagine, drafted a charter to assure the rule of law and the rights of man, a charter expanded by the blood of generations. Those ideals still light the world, and we will not give them up for expedience's sake."
--President Barack Obama, 1/20/09