Wow. This is awesome news if you own a PSP or know a friend who has one but has upgraded to 3.51/3.52 official firmware or just has a bricked PSP.
Basically, a few months ago details were leaked about a special battery called JigKick that Sony would use to unbrick PSPs they work on. I guess licensed Sony repairmen had this too and eventually the special software used for this was released on the net. It was useless without the special battery though.
Well now team Noobz have released an app that will unbrick or downgrade any PSP, and this MIGHT include the PSP Slim & Light too! (PSP-2000) It's SOFTWARE only, no need for a special battery. It uses a normal PSP battery to do it.
Site is here: http://www.noobz.eu/joomla/news/pandoras-battery.html
Some info and history is on there.
So now there's no worries at all about a bricked/messed up PSP! You can always unbrick it.