Guys, frankly I think its best to give up this discussion - none of us are historians, and even among historians, there is a lot of controversy and a lot of different interpretations.
I had the pleasure of speaking to a history professor in my university today, and what he said really opened my eyes to how difficult it is to make any accurate judgment about an ancient civilization, and how 90% of the research (even by very prominent historians) done on any civilization simply reconfirms old biases without actually coming up with any credible conclusions.
For example, the popular myth that IVC had a written script is pretty much busted - it was most likely primitive pictograms of some sort, which are very difficult to understand, and haven't been so far.
Another popular myth about their apparent rigorous standardization is not true either - most of the Harappan bricks are of irregular sizes and shapes, and their roads are not aligned along the cardinal directions as often believed.
Regarding Harappan trade, it turns out that the Harappans were actually a mostly agrarian civilization that did trade with other civilizations on a limited basis, but it wasn't the sort of over-hyped ancient "globalized world" as we have been taught to believe.
A lot of the stuff that comes up in popular newspapers and magazines (Time, NYT etc.) simply uses "sexed-up" interpretations of the most sensational claims in order to make the article attractive to the reader, and doesn't bother to paint a real picture of the civilizaton.
Finally, archeology is a boring, laborious job that takes years of work to make even the most basic claims, so frankly, I've come to the conclusion that if you want to discuss ancient history, go to a university conference. Don't chatter on the internet in 3 sentence paragraphs, out of which 1 is an ad-hominem and the other two are sarcastic remarks.