Starwood made an announcement on February 20, 2013, about the yearly award category changes that would take effect on March 5, 2013. I wrote a piece about the change that you can access here.
SPG said that there might be some further changes before March 5. One of the properties that moved up in award category was Royal Orchid Sheraton in Bangkok that went from category 2 property to category 3.
Now, Starwood has further upped award categories of the following three properties during the past 10 days:
Westin Panama from category 4 to 5
Aloft Miami Doral from category 2 to 3
St Regis Shenzhen from category 5 to 6
The award category of this hotel was changed on March 10th or 11th.
It would be good IF Starwood would give advance notice about these category changes. They just upped the award categories close to one fifth of their hotel portfolio and two weeks later they are already upping some more.
EDIT: Added the St Regis Shenzhen to the list above.