Can, and software to 'increase' resolution like Genuine Fractals will be good. If the object has smooth straight lines and not much fine details, certainly not a problem to print to 24" wide.
I have a poster of orchids hanging on my wall at 24" by 36" taken with my S2pro.
Printers need 175dpi images to start with, but the final print will be about 300dpi worth. This is how CMYK offset printing works. Plenty of info on the net, do a yahoo.
Film is not equivalent to 20MP. It is just that film grain and noise, when blown up large is soft and round, more pleasant and most people can accept it in prints. On Jpegs or even tiffs, the pixellation is terrible. 135 format film (used for 35mm cameras) is about 6MP when it comes to resolving details like a photo shot of newspaper classified adverts.
Magazines with needs for very high quality images will only accept medium format (120 format) film. 35mm just not good enough, although very protable.