No. HTML has no reason to specify information that has meaning to display technologies we happen to use now. Subpixel anti-aliasing is based on current LCD technology and doesn't even deal with newer approaches such as the PixelQi screen that equips the OLPC laptop (9 subpixels per pixel).
This solution would pollute the HTML information space.
A smart browser showing the same page spread over two different monitors would then download twice as much, but everyone else would be happy.