Any mini games that you purchase after 17th December will be available to download for both platforms, so you only have to purchase the game once in order for it to work on your PSP or PS3. Games that you purchased before the 17th will need to be downloaded again to play on the PS3.
Update 3.15 also includes a new PS3 Data Transfer system that makes transferring data from one system to another much easier and user friendly. Find out the full details on this latest update at the EU PS Blog.
Does this news give you something to look forward to? Which Minis would you recommend from the network store?