According to GamesIndustry International, Sony are rumoured to have struck a deal with "cloud-gaming" pioneers Gaikai that will allow them to make PlayStation 2 and PSOne games playable on "current-gen systems" using web streaming technology.
While Software emulation was used for PS1 games on PS3, PS2 backwards compatibility was only available on early PS3 consoles that featured the Emotion Engine chip, before Sony removed it from newer models to trim manufacturing costs.
Gaikai currently supports streaming for dozens of games, although only in regions where their servers are located (which does not presently include Australia) and up until now, has been limited to PC games. PC games from the likes of EA, Ubisoft and Capcom have been running on the service for some time, but achieving a comparable experience to running them locally is obviously heavily impacted by latency and bandwidth constraints as the system is effectively streaming hi-def video in real-time.
On the plus-side, it means that the device on the client end has to do only the minimal processing required to render the video -- a factor that has allowed Gaikai to get their hooks into retailer websites, Youtube and Facebook and TV manufacturer LG. So theoretically, it's technically feasible that server-streamed PlayStation games would be able to be played on any device capable of interfacing with Gaikai, although GI International points out that they have no word on whether Sony are considering allowing it's games outside of the PlayStation ecosystem -- even if only to other Sony products such as TVs, tablets and laptops.
Neither company have confirmed the deal, but speculation suggests that an announcement may occur at Sony's E3 press conference tomorrow. Nevertheless, the notion that it might some day be possible to play hardware-dependent classic games on any device with a browser is quite appealing -- presuming the limitations of cloud-gaming can be overcome.