take this as u will!!
and i quote
"while ford is using a much improved 6.4L ps in the 08, sources say the relationship between ford and navistar has soured and ford, a company w/ a long diesel legacy is already developing its own replacement diesel - a 6.7L v8 for the 2010 model year sd. ford originally intended to use intl's 4.5L v6 'baby ps' in the f-150 and has since dropped that plan for an in-house 4.4L v6"
taken from the may issue of 'fourwheeler'
a side note
the new ford ceo alan mullaly has gone on record as stating the entire ford lineup will be revamped by 2010, showing that ford knows new product is something it desperately needs...