1) You Don't Need One: Be honest, nobody cares what you're doing at this very moment and you know it. You're not interesting enough for anyone to wonder what you had for breakfast or what brand of laundry detergent you use. If you want to wear some form of sign that proclaims your importance to the world, feel free, but sending a glorified text message to that effect is self-defeating.
2) It is Not New: I'm talking to you CNN. With the ever-quickening pace of modern technology, it is disingenuous to proclaim a three year old service the cutting edge. The open embrace of Twitter by the media, public and politicians is both depressing and distressing. Mainstream media has entire speeches and reports to misconstrue, they don't need easily misinterpreted 140 character messages to work themselves into a froth over.
3) I'm Really Tired of Hearing About It: I really am. Example:
Thirsty plants can Twitter for water with new device