The concept of microblogging has been around for a while and is championed (based on userbase?) by Twitter. I for one don’t seem to get why and at the risk of making an ignorant statement like these,  I find micro-blogging in its current form (with exception of a handful scenarios) frivolous and useless. The main argument I hear about it is that twitter (or similar services) are the real-time web and unless Google or others move towards that, you will be losing the game by serving the users content that is not super fresh and real time. I can see that being the case eventually and maybe the current form is just a stop-gap to figure out how to get us there and just maybe that is why Facebook is so obsessed with turning into twitter to the degree that it changes the site to even look like twitter. And then you have Google to some degree drooling over Facebook and certain aspects of its model and Microsoft trying to catch up with Google. We have a full ecosystem right there with these four guys.
Here is a good video summarizing my sentiments on tweeting (thanks to Karina):

PS. I do have a twitter account (curiosity) but I think I have logged into it maybe twice in the last 6 months.