http://games.gearlive.com/playfeed/article/q107-ps3-firmware-170-adds-rumble-for-ps1-ps2-games-04182020/

Some nice features: 

1.  New PS1 downloads will be playable on the PS3 along with the PSP. 

2.  Game saves can be transfered from PS3 to PSP and vice-versa so you can play PS1 games on the road and then on your TV/Monitor on the PS3. 

3.  Rumble is back for PS1 and PS2 games.  Right now that means hooking up a dual shock 2 with a USB adapter but I'm sure that means future controllers for the PS3 will also work.

Nice update.  I can now start FF2 and play it on both the PS3 and PSP. 

Nice update this :D

 Since Sony got that business with Immersion behind them, and are now working to put rumble back in the system, I would say it is likely to help with future PS3 games. BTW, does that also mean a future update will allow the PS3 Guitar Hero controller to work, if it doesn't already?

Yeah, apparently now all PS1 and PS2 controllers work with the PS3.  Just need a USB adapter.  I've heard this also includes the Guitar Hero controller (for 1 and 2) as well as any rumble features.