Does that mean that it automatically configures between the two depending upon the game you're playing or does it remain solely on Geforce PhysX?
PhysX System Software above 8.09.04 doesn't contain Ageia PPU drivers and firmware anymore, so yes - it's up to GPU PhysX only.
But there is a way: you must install 8.09.04 firstly and then above them (without uninstalling) newer driver, 9.09.0814, for example. You'll get something like this - link
. Through both Nvidia and Ageia panels you'll be able to configure, what to use - PPU or GPU.
But remember - PPU performance isn't fascinating today, and its not supported by PhysX SDK 2.8.3 and above (let's say - 2010 games). Still, you can keep your 9800GT as dedicated PhysX card after next upgrade
Say if I'm playing such titles like: Cellfactor, Bet on Soldier, Infernal, GRAW, etc; would the drivers allow me to use my PPU in those games instead of the GPU?
You can't use GPU acceleration in those titles in any way, cause they are all below PhysX SDK 2.7, and only 2.7 and above were augmented with CUDA.
How can I confirm whether my PhysX card is being used when playing these games, instead of the Graphics Card hogging all the glory?
First - There is a thing called PhysX Visual Indicator, it can show whatever CPU or GPU PhysX is used in certain game (was made to give some clarity to users, still even games with GPU doing PhysX effects are using CPU for many physics calculations), but I dunno if it can indicate PPU work.
Second - there was method we called "Puppeteer method" in Ageia times - if you'll try to reset your PPU through control panel, warning will pop up if PPU is in use.
Still, best way to confirm is to set all setting properly through control panels.