I think that there would never be a succesfull new amiga now or in the future...
why? lack of hardware and all great hardware nowdays is for pc's... who will design let's say a better gpu than nvidia/ati? noone can , money is the main reason... so you make an amiga mobo coupled with the latest nvidia/ati chip, the latest sound chip etc... so? another computer can have that and propably use it better because of the greater user base...
even apple abandonned their "close" architecture... there was no point to it when the x86 hardware is now way better...