Just got an email from Rockstar Games. No details as of yet, but it lends credence to the idea of a "Streets Of San Francisco" themed 70s setting, perhaps. It's slated to show up in October 2004 on the PS2.
The sun was shining on the sea,
Shining with all his might:
He did his very best to make
The billows smooth and bright —
And this was very odd, because it was
The middle of the night.
— Lewis Carroll, “Through the Looking Glass”