The concept of creating a custom firmware package that will allow the best of both worlds above and below the 2.0 mark has been around for a while. Thanks to GameShark that’s all starting to change. He has created the first “custom” firmware package that has all the abilities of a 1.50 PSP, but has the added media capabilities and codecs of 2.0+.
At the moment, you can only run this custom firmware using MPH’s Firmware Launcher. Do not try to use this package as an actual upgrade.
I haven’t tested this yet as I am waiting for a non-beta release but I would be interested in the comments of anyone who has used this.