Apparently during the course of this afternoon someone at Twitter must tripped across a cord or a switch because some users saw their update button turn into a Tweet button on the web interface.
If you do a quick search on Twitter for tweet button you will see a mix of tweets that range from someone’s button changing from update to tweet and back again, those that still have Tweet on their button and others who want tweet on their button. There are even those who wonder if they really saw the word Tweet on that web interface button.
Rest assured Twitter World that you were not seeing things – apparently some level of testing was being done and some buttons really did say Tweet on them – some have even stuck that way!
Thanks to user @Orli, who grabbed a screenshot, you can put off your appointment to have your eyes checked:
You can see the original here – http://twitpic.com/17ks13.
By the way – I am still updating my Twitter.