Apple had not sued anyone for doing so before this became technically "legal".
Regardless, this doesn't change anything in regards to being against Apple's license agreement for the iPad, is not supported by Apple directly or indiirectly via these discussions, and voids Apple's warranty if the iPad remains under warranty. And last but certainly not least, opens the iPad up to signiifcant potential secuirty concerns that is otherwise not a concern with an iPad that hasn't been hacked. Installing pirated and non-official software - software not available via the iTunes app store being "legal" is the least of your concerns. Such software can and has included malware and spyware. No different from downloading pirated and other software from unknown and untrusted sources with your computer.