Typing "I hate <company>" into Google is the same thing. Twitter just lowers the barrier to entry (for writing "i hate foo").
I don't understand why this community nor the digg community does not see the immense value of indexing short conversations of millions of people? After all it's information and what does Google index and make billions from?
Heck of all the people I know I can't think of a single person that uses twitter. However I can think of a dozen or two that have written product/service reviews somewhere on the internet, which would be indexed by Google.