Barg,
Yes, the pastry is mixed into the potato mixture. They are so good and will disappear as fast as you can put them out, so I don't think you'll have to worry about them being room temp.
Something that I also love is the Smoked Oyster Roll that Sylvia posted a long time ago at the old Gail's. I think she may have posted it here too. It's so simple and so tasty. I don't have it here with me, Sylvia, you around?
As for desserts that pop, we always go for the grand over the top Central European tortes that take a day to make and assemble. I've posted several here, the Mozarttorte is our usual "pull out all the stops and knock 'em dead" dinner party dessert. The shortbread layer, while simple, really just takes the torte to another level.
Another really good one, and not that hard, is a French Concord Cake. I don't have the recipe here, but you make chocolate meringue and pipe out 3 Layers onto parchment lined sheets, filling them in with concentric circles. Bake these. Also pipe out long thin strips of the chocolate meringue, bake these and set aside.
Now pull out your Julia Child and make a nice Mousse au chocolat (probably need two recipes or so). Now assemble the layers with the mousse, cover the whole with more mousse. Break up the meringue strips and cover the concord with the meringue pieces. Refrigerate until ready to serve. This one is killer : ) I can get you the actual recipe later if you'd like more specific directions.