This is to update a thread a while back about polytonic Greek text on android.
I recently installed the Opera browser available in the app market on my Acer Iconia A500, and found that it does indeed do polytonic Greek, at least on this system. I have viewed a blog with some Greek text, Perseus and in the Text it forums.
The only drawback is that the text seems to come out in different font sizes, sometimes even within words. Oh well, it's a step forward, I suppose.
It is listed in the market as the Opera Mobile Web Browser and is version 1.11.