This is truly bizarre, but I've validated it on Safari and Camino on OS X, and I think, on Firefox XP. I have more than one blogspot account, and it's the same on all of them. It occurs at home and at work.
I can't click into the "Title" field in either the BlogThis! post submission widget or in the blogger editing environment. The cursor won't move into the field. I have to tab into the field, then use the arrow keys to move a cursor around.
This has been going on for a week for me. I figured it was so outrageous Google would fix it by now, but now I wonder if it's simply the universe conspiring against me.
I think I need to stop reading books about probability wave collapse; the world is just getting too peculiar.
Update: Ok, it's a bug. Phew. Why the $#!$#$ doesn't Google/blogger announce this in their !#!$%$! status page?!
Update: It's not just the title field. A lot of the controls on the BlotThis! widget no longer respond to mouse clicks. Grrrrrrrrrr.
BTW, you can vent your spleen here ...