4 megapixel ok for 8"x10" prints?

[Steve Kane]

I'm thinking of getting my step-son  the 4 megapixel Olympus C-750 UZ. 
I know he will enjoy the longer zoom, lighter weight, and smaller size 
of the C-750 compared to say the 5 megapixel  Nikon Coolpix 5700 or HP 
Photosmart 945. OTOH, I know he will sometimes want to make 8"x10" 
prints and would be disappointed if they are too "grainy". I've made 
8"x10" prints from my 5 megapixel Minolta Dimage 7i and even with a bit 
of cropping they look fine. How will 8"x10" prints from a 4 megapixel 
camera compare?

Thanks.