@Harrison

It is not mad to release 4.1, it's essential.
There are legal issues involving trademark ownership which are often awarded to the side that haven proven usage as apposed to just registered.

There is also the financial element.
If Hyperion are fighting the court case, we can assume they want to do something with the OS.
To sell copies of it for other machines if/when they win the court case, they need to keep developing it to keep it modern.

In which case, it makes sense to make some money along the way where possible.
Nothing is lost selling copies of something they already have.