The Future of Captcha?

I saw an interesting post on forrst.com this morning which was a screenshot of a planned method for making Captcha easier for users and still stop robots / spammers from filling out your forms.

Captcha at the moment requires users to decipher a series of distorted characters and enter them in a text box to confirm they are actually human.

The concept behind the new idea is to use a slider instead of entering characters. They Make Apps use it for their sign up form.

Personally I think it's a great idea however implementations need to be throughly thought through to ensure it actual does the job of what it is supposed to do.

Possible solutions could be made using flash, Javascript or even HTML5.

I am not sure if it will take off, but I really like the idea. What do you think?