It's all a very much o.O to me.
Why on earth would I want someone out of arms reach know what I am thinking?
Well, in general, people like to communicate themselves to others, and to hear others communicate. It makes more sense if you realize that the act of communication is often an end in itself, not simply a means. And there's also the fact that - despite the occasional act of bullying or violence - most humans are fairly decent and will happily accept you into their "tribe" if you can relate to their own inner thoughts and desires.
I don't mind the increasing publication of personal thoughts, ideas, and philosophies. In history (a very general assertion here), the greatest eras of development, invention, and toleration are found in those societies where communication was least hindered, and people were most willing to communicate their ideas.
And yes, 99 out of 100 ideas suck. But those ideas tend to be discarded in the end, or improved upon, and that 1 great idea often sets mankind forward by centuries. Now, there are those who don't see more knowledge, more technology, and more intelligence as good things, but I can't count myself among them and hope that they are few in number.
As for blogs and etc making it easier to manipulate us, I rather doubt that. The greater the number of voices, and the greater the diversity of opinions, the more difficult it is to control them. Convince a person that they are the only heretic, and they will shut up. Let them know that every other person in the nation feels the same way, and the despots and tyrants will find their reigns increasingly founded on the most desperate and slippery of foundations.
As for a consumer culture, the reason we have a consumer culture is largely because humans are consumers. We always have been. We like shiny things, we like new things, and we like being special and being seen and heard. And, not only that, most of us tend to like other people getting shiny things, getting new things, and being seen and heard. It's not some complicated cultural thing - almost every human from every age in history, will prefer air-conditioning, a new computer, and a nice car to whatever circumstance you pulled them out of. Our products, our markets, and our media are conformed first and foremost to our innate desire for comfort, amusement, and sustenance, not the other way around. It's easy to show this - for example, the Catholic church has spent about 2000 years trying to make sex more of a duty than a temptation, and they've utterly failed. They failed even in the middle ages, at the height of their cultural power.
Indeed, one could argue that religions pretty much make their profession off of asking us to deny what we are in some particular, and while this doesn't necessarily call their veracity into question, one might point out that they have been spectacularly unsuccessful in the majority of cases. Given this, we could well question the capability of a corporation to, in a few advertising campaigns, manage what far more sophisticated and well-designed systems of propaganda (I use the term in the non-prejudicial form) have not. And, from what I have studied in advertising, I can't say that most corporations are trying to brainwash you - actually, most of them are simply trying to get you to remember them when you need the product they offer.