I happened to order from China Palace tonight. In the bag with my food was this note.

The owners of China Palace own the building (4511 N. Oakland) that contains the restaurant. As such, their closing may be an indication that a sale of the building is pending. Also located in the building with China Palace are a small grocery store, and the North Star Bistro.
At this time, I have no specific information on who the new tenants or owners might be. Rumors were flying back in November of 2007 regarding a potential sale of the building, but I have not heard anything since.