Why bother bring it up to date? The nostalgia is what we all love about it. I don't want an Amiga with an Intel processor, I have a modern computer to do modern tasks like surf the web and edit photos.
The Amiga is now a 'retro' computer, so the only way to spark new interest in it is to keep the original hardware (remember there are thousands of new A1200s out in India that are slowly being shipped back to Europe) but to start writing new SOFTWARE for it. I would happily buy 'new' games for the Amiga if people were writing them, I love the old-school look of the 16/32 bit era games, and the playability of them.
I'm sure that if anybody could be bothered to start making new adventure games, platformers, shoot em ups etc (the games that made the Amiga famous) then not only would lots of current users buy them, it would re-spark interest with old Amiga users.
So in summary, forget bringing the hardware up to date, we need new, high quality software. How cool was it to play Putty Squad for the fist time over Christmas!?