If Sony just allowed the PSP to run homebrew games, they'd not be in such a mess. Many of the developers rooting the devices just wanted to run their own software, but the shadow community would use that result to pirate games. Separating the two communities by allowing homebrew software on their device would have made sense for their own protection.
This was then followed up by the PS3. After releasing with both the ability to run Linux, they removed both. You paid for a device with X, then they removed X. Understandably the community became somewhat irate. Eventually their private signing key for their entire console was leaked due to the desire to allow homebrew and to restore OtherOS (Linux) support[2]. Sony's legal department tried to fix that...
So, from all this past history, I wouldn't trust Sony's new direction. At the very least not until they start to act on their new found conviction.
[1]: http://en.wikipedia.org/wiki/PlayStation_Portable#Homebrew
[2]: http://en.wikipedia.org/wiki/George_Hotz#Hacking_the_PlaySta...
Edit: Thanks for Dylan16807 correcting me re: PS2 emulation. Having a deeper read into it, the situation is confusing -- some models have hardware PS2 support, others do emulation, and then it was completely dropped whilst "PS2 Classics" (recompiled or via emulation) were released on the PS3 as pay for downloads.