Again (I love these threads which pop up once a month or so)... The thing that is always forgotten was that the Amiga wasn't really revolutionary for its time, rather it simply solved the technological issues of the day in a revolutionary and efficient way. If you were to make a "True"(tm) successor to the 1985 Amiga 1000, you would need to solve the technological problems of today.
Computing requirements now are almost fundamentally different to what they were 26 years ago, let us make a list of what a user needs from a computing device now;
1. Mobility
2. Connectivity
3. Compatibility
4. Usability
5. Low power consumption
If you work through those you will probably end up with something not unlike an iPad... Hopefully better, but fundamentally the same...