I doubt we will ever see an ad blocker from any commercial entity. Unless, of course, ad blocking is the only motivator behind the entire business. Somehow, I don't really expect that either. Consumers of ad blocking software probably wouldn't be the kind of people who pay for things like that :-)
As such they don't really lose anything by taking away Google's core business in the form of an ad blocker. Microsoft has always been very worried about Google, and Balmer has compared Microsoft and Google as rivals in the software industry. If Microsoft can leverage their control over browsers in IE8 with an ad blocker, then they can potentially take a large chunk out of Google's bottom line, and make Google a much weaker 'rival'.
Say what you will about Microsoft, but they depend on armies of developers who depend on ads. As such, do not expect them to produce an ad blocker. It would be nothing short of a developer relations disaster.
assuming it's altering the content of the site it's directly violating the copyright of the site.
That is a more accurate analogy. It's stealing and depriving the publisher of their income.
In any event, getting past adblockers is really really simple. It always will be, and if you think an adblocker can block anywhere near all adverts, you should go read up on how things work.
To suggest that blocking an advert is stealing assumes that the author of the web page would make money off that advert in the first place. Furthermore, that logic suggests that anyone who chooses to ignore advertising rather than just blocking it is also guilty because they're depriving the publisher of a potential income too. Total rubbish.
You are stealing bandwidth, processing power, storage, electricity, etc
Society is about give and take. Adblocking is about take.
Do you click every advert you see just to make sure you're compensating for 'stolen' bandwidth, processing power, storage, electricity?
FYI: I redistribute scripts under GPL licensing. I don't ask for donations, nor do I litter my pages with advertising. I consider that pretty "giving" - and no, I don't have problems with people 'stealing' my bandwidth, processing power, storage or electricity.
By blocking all advertising on all websites you're sticking your fingers in your ears.
Personally, I find adverts useful. Websites that resort to crappy user experience adverts - popups/unders/flash etc usually aren't worth visiting in the first place.