Possibly. I wouldn't put my house on it, but it could happen if Gasquet doesn't implode. I don't think he needs to hit Wimbly 07 form to beat Nadal on hard.
It would come down to the fitness i think.
If Gasquet has really improved his fitness during this off-season then he can definitely beat Nadal on hardcourt.
Ffs if even guys like Simon and Monfils can do that then why not Gasquet?