eiru_hide_Tax/views/product_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record id="product_product_inherited" model="ir.ui.view">
            <field name="name">product.product.inherited</field>
            <field name="model">product.template</field>
            <field name="inherit_id" ref="product.product_template_form_view"/>
            <field name="type">form</field>
            <field name="arch" type="xml">
                <xpath expr="//field[@name='taxes_id']" position="attributes">
                    <attribute name="invisible">True</attribute>
                </xpath>
                <xpath expr="//field[@name='supplier_taxes_id']" position="attributes">
                    <attribute name="invisible">True</attribute>
                </xpath>
            </field>
        </record>   
    </data>
</openerp>