1) close enough. PPC are completely different cpu architecture to 68k, but with an "emulation" core built-in to help Apple make the transition all those years ago.
2)the A1 and Pegasos are both ppc platforms and support PCI and AGP. Not sure of how much memory you can stick - 1Gb at least? (2x512Mb)
3) Linux runs on both boards. Mac-on-linux runs very nicely on A1 and presumably Pegasos too. AmigaOS4 will run on A1. MorphOS runs on Pegasos.
Infighting between the two main factions and ebullient swaggering from various development leaders has more or less killed the opportunity of you purchasing one board or the other and then running one OS or the other (probably the preferred option for the silent majority)
The A1 is (will be) an Amiga because it will run AmigaOs. The Pegasos is not an Amiga, because it won't officially support AmigaOS. MorphOS is a new OS that began life on the old phase5 PPC boards. Both will run AOS3x apps using different emulation methods. Most modern apps (with rtg and rts) will probably run fine. Your mileage may vary with other Classic apps and games. Both systems will run UAE well enough to play A500 games.
Both A1 and Pegasos shipped in small amounts with G3 cpus. The updated A1-XE (with G4 at 800MHz) has shipped to many developers and is going out to consumers anyday now. The Pegasos is undergoing similar revision (and theoretically some nice looking extras) to be released in September. All announcement dates should be taken with the usual pinch of salt.
The AmigaOne-A1200 bridge board is highly unlikely to appear in its proposed form by Escena. Our best hope is Jens
Most of the Amiga sites are poorly maintained as the folk developing the system are strapped for cash and working very hard. Your best bet is to flick through Amiga.org and Ann.lu and try to filter out the posturing.
Most Pegasos sites look pretty, because Genesi seem to have too much cash to flash.
