I wouldn't suggest feeding potatoe. Rabbits -can- eat potatoe peels, however, it is considered a food to avoid (along with iceburg lettuce, legumes, ect.) because of a rabbits' inability to digest it properly. This means feeding can be 'toxic' to your rabbits' digestive system, causing the runs, which could then ultimately lead to death. A rabbits' digestive system is very fragile.
Just because potatoes are natural, doesn't mean they're safe too. Consider this, potatoes are a 'root' vegetable. Rabbits do not generally consume 'root' vegetables--they consume herbs and other roughage that grow above ground. Most wild rabbits (from which our domestic rabbits derive from), would probably never come into contact with potatoes, or dig them out in order to consume one. Being incredibly starchy, rabbits of any kind (wild or domestic) will have problems digesting a potatoe.
It's also important to remember that domestic rabbits aren't wild rabbits. They do not know what is or isn't safe for them---it is up to us to provide them foods we know are safe. Just because a rabbit willingly eats it doesn't mean it is good for him/her. Many dogs/cats lick up antifreeze after all, and that's poisonous. Animals eat things they shouldn't because they don't know any better---they place their trust in us to only provide them access to safe things to eat (we are, after all, considered the 'alpha').
So, to answer your question...no.
Your rabbits' diet should be composed of a quality alfalfa pellet with no more than 18% protein and 23% fiber. It should be green and smell fresh. It should not contain corn. The general rule of thumb is 1/4 cup for dwarf and small rabbits. 1/2 cup for medium -large rabbits. And 3/4 cup for giant rabbits. This is per day, mind you.
In addition a rabbit should get as much Timothy Hay (or a similar grassy hay---NOT alfalfa--they get plenty in the pellets) as they want per day.
Supplement that diet with fresh herbs...parsley, basil, celery, mint, clover, and cilantro. Include other vegetables too...like broccoli (the crowns/leaves only..no stems), zuchinni, romaine lettuce, green pepper, and so on.
You can also provide some fresh fruits occasionally. Fruit is harder to digest because of the sugar content, so feed sparingly and only in small portions. Bunny favorites are banana, papaya, and apple (no seeds).
A full list is available here:
www.mahouserabbit.org/infopack.asp
Hope that helps.