Sandy bridge based CPU will debut next Jan. I think they will be perfect for silent fanless HTPC build especially the 35W TDP core i3 and 45W TDP core i5.
Here is the latest release date for Intel Sandy bridge CPU and price.
Now to the motherboard.
Intel H67 mini-ITX motherboard. The HDPLEX H3 chassis has been redesigned to fit mini-ITX board which 24PIN ATX plug is on the side. So this Intel H67 mini-ITX board will work with HDPLEX H3 series fanless computer case.