Not really. Usually having less than 3.0ns RAM chips indicated a non-Pro due to lower memory clocks, but some non-Pros have 3.0ns RAM or 2.8ns RAM, so unless you stick the card in your machine and check the speeds, you can't tell.
And if someone has taken a 9800 non-pro with 3.0 or 2.8ns RAM chips (Samsung) and flashed it to 9800Pro BIOS, there is no way to tell whether it's a true 9800np or Pro, AFAIK.