If you’re one of the lucky people who own a first-gen PS3 model (back when WiFi wasn’t standard and shit), your system has what’s called an Emotion Engine chip. Think of it as an extra heart for your PS3 that allows you to have a full Playstation 2 inside. Sony removed it a few years back to cut costs and now only a very limited number of titles are supported. To boot, Sony is also selling a lot of PSX games on the Playstation Network, so the incentive to add the EE back into the system is low.
But there is hope. According to a patent filing from last year (December, specifically), Sony is working on a way to compile and decompile the Emotion Engine. This will allow PS2 backwards-compatibility through software emulation, thus keeping us fanboys happier than ever.