Thanks for the link.
I hope this tatement in this duscussion has a achance:
I would guess (purely speculate) that there will soon be an unofficial way to install rosetta. Someone will determine which kexts etc. are needed to run rosetta and then you'll be able to copy those over from an OS X 10.6 install. Just guessing, but I can't see why it wouldn't happen.
I haven't tried installing Rosetta in Lion, but to me it sounds like at the moment Lion is simply asking itself the question "is this a PowerPC application?". If yes, just fail. Doesn't sound like its even loading the extensions, but someone should check in Console for errors. There may be nothing wrong with Rosetta kext's, because Rosetta already previously worked in Snow Leopard with the 64bit kernel.
An example where things aren't quite so sunny.... I tried to bring native read/write ZFS support to Lion using the binaries from Snow Leopard beta 10a286. But, it fails because of the 64 bit kernel, and expects symbols in libkern which aren't present. As such, Lion can't load the extensions. It should be possible to get ZFS working by applying a patch for the missing symbols and re-compiling libkern from xnu sources (which worked for SL builds 10.6.1 and beyond).
I predict no Rosetta support in Lion GM build... because Apple has been shipping Intel Macs for over 5 years..... thats half a decade....