Thank you for your inquiry. Checking the Technical Product Specification http://downloadmirror.intel.com/23089/eng/D54250WYB_D34010WYB_TechProdSpec06.pdf
Shows to addition USB headers.
But for the exact total USB hosts and if possible to use a mini PCIe card will need to check with engineering to verify and provide you with the correct answer. As soon as I have the information I will be answering your question.