A while back I started publishing the Twitter Self-absorbtion Index, an index measuring how much of the Twitter conversation was just inane conversation about how to tweet. When I started publishing, the index was in the 30% to 40% range (i.e. 30-40 of the top links found on Twitter were about Twitter), but thankfully, that has given way to general usefulness.
As a consequence of that, I have stopped updating the TSI. The full history of Twitter self-absorption from when the index was conceived, and updated hourly since then, is archived here for posterity.