I have received an email from Someone Who Says He Knows, saying that the freedom accorded by Summorum Pontificum to the Extraordinary Form is indeed under threat, and that the 'clarification' document is about to be signed.
This would be a very good moment to sign that petition, if you have not already done so.
I really don't know what all this is about. SP has, if anything, brought peace to this matter, and caused very little disturbance except in the minds of those who simply don't want us to be allowed it.
It's really quite simple; if you don't like the Extraordinary Form, don't go to it!