For a lengthy discussion about Rosetta, see here.
Rosetta was actually Apple's name for software called QuickTransit, originally developed by Transitive Corporation, which was taken over by IBM.
Apple was paying $$ millions every year to Transitive/IBM for the use of it, so it's understandable that it allowed the license to run out. Apparently that was a strategic decision that could only have been taken by Steve Jobs, no doubt advised by his other directors that it was costing Apple too much. Maybe they tried to renegotiate the deal but were unsuccessful. Only an Apple insider would know what happened.
It would appear now that the only way of getting something to replace Rosetta would be for enough people to petition IBM to come up with a version of it that can run in Lion. But it would have to interact with Lion, so I can't see how that would work.
There are versions of it for Solaris and Linux (but I think they're old).
I for one would be willing to pay for something like that but I don't see how it's possible.
So I think we're ****ed. Apple seems not to care that there are millions (repeat: millions) of users out there who at a time of economic difficulty suddenly find themselves faced with the expense of buying new versions of expensive software, or doing without.
And I've also noticed in these forums that quite a few people installed Lion without realising that it wouldn't run PPC applications, and are now in big trouble. Apple fanboys just say those people are stupid for not knowing it was going to happen. Fanboys don't understand that most people don't avidly follow everything Apple does on a daily basis.
I myself think that those millions of users deserve another option: the option to pay for a bolt-on version of Rosetta. Surely that would keep everyone happy?
Except for the fanboys, that is. 😁