It has:
- 256-bit GDDR5
- 800 Stream Processors/Shaders (It's stated that it has 640; that's en error.)
-700Mhz Core clock, 750 Mem clock
- 1GB VRAM
-DirectX 10.1
http://www.newegg.com/Product/Product.a ... 6&Tpk=4860
It seems to fit in between the 4850 and 4870.
It's sold for $134.99CDN / $129.99 USD.
I guess AMD/ATi's using up the remaining 4800 chips

EDIT: There is a 512MB version, but it's not on newegg...yet.
http://www.sapphiretech.com/presentatio ... 3&sgid=914