My bet is that she really is waiving the rest of the proceedings and asking for the DP. Here is the way I got to my conclusion:
First, she gives her attorneys notice of her intent to waive, and that explains the "heated discussion" widely reported last night.
Then she gives the infamous FoxTV interview where she reasserts her claim of desire to have the DP over life in prison.
Next, she is given special visitation with her extended family at the prison - I read here that it was the first time she has spoken to her Mother since the start of trial. She probably informed her family of her choice at that time. Jean Cesares reported that her Mom, when leaving the jail, told her that she didn't know if she would testify or not at the mitigation because she didn't really know what was happening - but JC said it seemed like she really wanted to testify.
She was transferred to a psych ward after the family visit.
And then we have the unexpected delay until Wed. We know she would be subjected to a mandatory psych eval if she was going to waive.
Last, but not least, we heard that Martinez and TA's family were seen smiling later today after being together in a room where it sounded like they were "watching news" - so they were listening to the interview tapes from the Fox piece.
I am not sure, but all this adds up to a very believable scenario for me that she really is trying to waive the rest of the hearings and go directly to the DP. That would be great for me, since I really am against the DP, but I have no issues if someone is really asking for it!