Err I would hope not!
Why is it that you would want a certification if you failed?

You want a certification because you completed the class ?
This sure would water down the any usefulness of "Udacity Certificate" alright.

Hey you know, check your spam box, I get offers to get certificates from great universities often.
True story!

The 'fail' tag is very appropriate for this thread

If you fail (like I guess will happen to me, by lack of time) you have another chance to try again in april, and if you fail in april, you can try again in june. I guess that printing and hanging a certificate in your wall makes much more sense when you are able to fully understand whatever the certificate refers to.

I would prefer a certificate as in "It shows that I know how to program a search engine" instead of "wow, cool, free certificate!"

It upsets me that I probably won't pass this time, but surely, next time I try I won't have my real university at the same time "stealing" my available hours, so next time I will do better and the certificate will make much more sense.

Do you get certificates from your college/University even though you fail just for attending the class? If yes, then you can certainly expect, but i don't think so udacity will offer you such highly imaginative award. Udacity is trying to giving the best for no cost, they are also trying to make sure everyone gets a good grade, but in logical way by improving the quality of students and teaching them interactively. Why no take advantage of that instead of hoping for what you don't deserve?

Of course. It'll say "Congratulations, red. In opposite land, you were our best student!"

in my opinion you would only fail if dont learn anything you didnt know before.

I read it somewhere that many years ago an ivy league university was giving out A's to all its graduates. Students were graduating with straight A's and with great recommendation letters. At first, industries didn't realized it; so they hired the graduates right and left, only to find out that the graduates knew very little of anything. For years after that, the industries stayed away from hiring anyone from the university. --A true story. I do not want Udacity to fall in to the same pit.