That IS true - the .NET is less valuable than .COM, however, in some cases, .NET is prefered, like when you offer active services.
If I were to run a school registration web site, I would prefer registrations.net to registrations.com because of two different ideas.
As for .cc, .tv, .info and .biz, etc, their value is very low. There are currently plenty, and I mean PLENTY of beautiful one-word .info names for sale right now for quite cheap (under $50). Nobody wants them though. .INFO won't work for at least next 5 years. And then new extensions could be introduced...
I, for one, made a mistake recently registering tennis.chat and tennis.club domains at new.net services. As I found out later, they work only within the New.net environment - those who downloaded a plug-in or use certain ISP to connect to the Internet. Everyone else can't access it. That's why the names were available. Plus, too expensive. I see no future there whatsoever, unless they'll make them universe.
Hope this helps,