Captain:
It sounds like you have discerning ears and you're able to confirm what most audiophiles think of MP3 audio. Certainly using higher bit rate conversions up to 320 kbps will help improve the sound, but the file sizes really aren't that much smaller than a 16-bit/44.1 kHz .wav file when you consider what you've sacrificed in sound quality. Most people who listen to music really don't "listen" to their music, or the music they listen to isn't well recorded to begin with. I listen to MP3s as samplers, but I listen to CDs and LPs for the experience.
Perhaps the closest you'll ever get to .wav file quality with data compression is to consider Sony's ATRAC data "lossy" compression which is used for their Minidisc format. Some Minidiscs actually sound pretty close to the original CDs from which they were recorded--certainly much better than MP3s. ATRAC compression is Sony' proprietary technology, so I don't think you'll be able to get an ATRAC software encoder. That creates a problem in having to get a Minidisc recorder/player with digital I/O for transfers to and from your PC.
As for me, I am waiting for Apple to come out with the next generation iPod capable of storing .wav files for PC users. Only Mac users can access and archive .wav files on their iPods at the moment, and I am a PC user.