A passage from Twitter CEO Evan Williams’ post why the new, formalized Retweet function "works the way it does" shows lack of depth and clarity in Twitter’s thinking about the significance of trying to replace the "Retweet" (RT) forwarding convention, something that arose organically from its community without any assistance by the company whatsoever:

The attribution [...]

Only 2 (!) simple lines of code to have avatar support for your Wordpress comments with gracefull fail-over from Gravatar.com to Mybloglog.com, all without plugins… just add to your comments.php in the comments loop wherever you would like to see the Avatars/commenter photos placed:
The code for gravatar image URL is taken from Tom Werner’s [...]