Found out about Music Giants off the Wired feed. It’s another itunes lookalike, but with very high bitrate downloads, at $1.29 a pop. If only iTMS would do the same thing, I’d be all over that.
Music Giants is WMA lossless only.. though one might imagine a system where you record the bits as they go by, write them out, and then re-encode them as Apple Lossless or something.
Either way, the real ideal solution looks like this: When you purchase a song from iTMS you get a high bitrate version that goes on your hard drive. iTunes has a preference, that says what bitrate you want songs to go on for your iPod. When it comes time to copy songs over, they’re converted on the fly to low bitrate versions.
It sounds computationaly expensive, but weren’t there stream encodings for these things that encode the finer detail at the end of blocks, which can be discarded if they’re not needed? i.e. a 128kbps file’s data is a strict subset of a 360kbps file (On my listening setup, 360kbps ogg/mp3 is about the level where I can’t seem to tell the difference anymore. I haven’t expiremented too much with what the equivalent bitrate for AAC is.)