What Is “Experimental Interface” Nowadays Anyway?

Learning in class and books about usability, standards and what-not, how do we evaluate an interface as experimental? Is experimental bad? Or to put it in the proper context: when building websites that are for people (and not for winning awards and peer recognition), is experimental or non-standard design considered bad design? I submit for your consideration the following websites:

• Stijl On Web
• Chromazone Imaging
• httpcomunicacio
• Honda Sweet
• NID Gallery

I ask this because the project we’re working on has potential to go in either the “traditional” or “experimental” route (I’m starting to hate the word experimental). Now that I think about it, is something only experimental when it hasn’t been overdone 1,000,000,000 times? I think experimental doesn’t really mean bad or unusable, it just means that it isn’t standard, and whose to say it’ll still be called that in the coming months (or days)?