fwiw, it's pretty hard to hear the difference between 320kbps mp3/AAC and CD/lossless. like...you really have to have some good equipment or it won't matter a lot, as most headphones and speakers don't even get up into the high ranges of frequency. BUT...you will notice a distinct difference between say...V2 mp3 and FLAC. so if you have a lot of stuff <200kbps, it may be time to re-rip your stuff to higher quality.
and yes, I've started to create and collect FLAC as much as possible for the important music. you can always transcode FLAC to mp3 for regular, convenient listening but keep the flac for storage or serious listening sessions or something. I just think that whenever you can have a flawless, lossless version of something really good, you should probably take it. that's why I pre-ordered this CD. it will be immediately ripped to FLAC and stored with my other FLAC stuff.
Cheers. Glad to have been helpful.