Dell Inspiron 1525 Mini PCIe slots

Ok, I have a quick question I hope someone can answer for me. Right after I bought this laptop, I removed the bottom cover to upgrade the ram. What I found inside was (3) Mini PCIe slots. One was filled with a WiFi card that I also upgraded while I was in there, but the other 2 were empty. I know would bhe for a WWAN modem, but I will never use it. The other one was marked UWB and is unfamiliar to me.

What I want to know is this. Am I able to use any PCIe card I want in the 2 extra slots? I have researched and found that some of these 1525's shipped with an Intel Turbo Memory Cache card, and if I read it right, I should be able to install it in the WWAN slot. What I am interested in doing is adding a this cache card, a HD PCIe decoder card (in the UWB slot), and a BluRay drive to replace the DVDRW drive. Is this even possible or worthwhile to do? Thanks!