HP is expanding its business tablet lines with the ElitePad 1000 and the ProPad 600. While the ElitePad 1000 is a refresh of HPs existing ElitePad 900, the ProPad marks the start of a new product line for the company. The $739 ElitePad 1000 will be available in mid-March while the ProPad 600 is expected to retail in April at a lower price than the ElitePad.