Sony have just gone ahead and announced the update to the PlayStation 3's firmware. 3.15 will open up support for the PSP Mini's to now be played on your PS3 with an emulator.
"If you buy a minis game from the 17th it will work on both platforms so if you have a PS3 and a PSP you will only need to buy it once and it will be available to download to your PS3 and your PSP.
If you have already bought a mini for PSP and want to get it on your PS3 as well, just go to your download list in the Store and download it again for free. The game will then work on your PS3 as well. Simple!"
You can check out the rest of the details over on the official PlayStation blog. Still no sign of cross game communication, maybe in 4.0? Who knows...