[Evisse the Blue]

It's interesting that reading the description of Hobbits one can see why 'they were meant' to be the heroes of this book.

1. 'A people of no importance'
First of all, little was known about them by both Elves and Men; their origins and early history are a mystery even to themselves. Even afterwards they appear in very few records. So it is very likely that the Enemy would be unaware of their existance, of their strenghts and weaknesses, and very likely to underestimate the former, once he did learn of their existance.

2. Appearances are deceiving
Although their are fat, small and appear lazy, they are nimble, swift, skilled at bow and arrow and stone-throwing, and 'curiously tough'.

3. The art of dissaapearing versus the magic of dissapearing
As it has already been brought up in this thread, by Fordim and Davem, they are distinct and meant to express opposite things. Whether this is just a well-placed irony (they already can dissapear, so they don't need a Ring to do it), or an attempt to make them more familiar to the reader, it's still debatable. But it's clear that a hobbit's art of dissapearing is closer to nature, similar to an animal's becoming one with the scenery in order to avoid predators.

4. Basic needs and pleasures
The simplicity of their thoughts and desires make them less likely to be usurped by the more sophisticated 'lust for power' that the Ring evoked.