Interesting article to read posted at TechCrunch regarding the new gTLDs availability to register a domain name using different extensions 1000+ of them from .GURU .NINJA .anything you can think.
In my humble opinion. I think the new gTLDs are good for personal blog and website. But I will not recommend this for a business use as your primary site for online e-commerce. Why will you build your online business using anything.extensions to give free advertising to the owner of .com domain? Where you work hard to establish your online brand, spending time and money to spread the words to all the people you knew about your business.
People knows .com is a trusted website to conduct business, plain and simple to do business online. This is also the reason I rebrand from KING.NET to QUE.COM, yes it's not an easy task and not cheap too. This is why I always recommend to my clients, do it right the first time get your business a .com domain name.
I will registered other extensions to support my business, redirect it to my primary site, and use it for marketing purposes only. But never as your primary website. I hope that makes sense.