Some thoughts:
1) I like the stand but 70 bucks for the case/stand combo is absurd. It would have been great if they'd built the tripod socket directly into the unit. Thanks for the suggestion of the Treo case. Maybe I'll try to come up with my own tripod adapter if I buy an R09.
2) That's very good news about the battery runtime. I don't think WAV should give less recording time than MP3 by any significant margin. WAV doesn't take any significant CPU, it just digitizes the sound and copies the A/D output bits directly to the flash card. It's MP3 encoding that's CPU intensive. WAV writes a bigger file, and writing to the card takes some power, but that shouldn't be a large effect.
3) I'd be interested to see runtime measurements for playback. Could the R09 double as a general purpose portable player (instead of an ipod)?
4) I'm pessimistic about the 4GB SD card situation. That message from edirol about the directory structure doesn't make sense. There's a 2GB limit on FAT16 filesystems but that's a FAT16 limitation, not an SD limitation. It's solved by FAT32 (which has a 2GB limit per FILE). There was a 2GB -hardware- limitation on SD cards til recently but the current standard goes up to 16GB, and Patriot has already announced 8GB cards. (The coming SD/HC standard goes to 32GB and has some speed rating standards intended for use by SD video recorders--existing SD cards should be plenty fast enough for audio). Many PDA's support 4GB cards so there's no good reason for Edirol not to unless they are hardware constrained. "We haven't tested 4GB cards" sounds bogus to me--Edirol like anyone else is capable of getting a retail 4GB card and popping it in the unit, so if they haven't done that and said that it works, that means it doesn't work. So, I think the 2GB limitation is a hardware limit that will NOT be fixed by a firmware update.
5) Re retaining settings and time/date info, the R09 improves on the R-1 but still messes it up IMO. Any digicam or camcorder remembers settings and the current time across battery changes, maybe using a watch battery, so they should have done the same thing in the R09. The PMD660 (in other regards an inferior unit) also remembers this info, though I'm not sure if it has a separate battery for that.
6) As mentioned elsewhere the absence of a digital input is unfortunate. It would be great to use this with an external A/D converter.
I'd almost certainly buy an R09 in preference to my PMD660 if I didn't already have the PMD660, but as it is, maybe I'll wait for an updated version of the R09 before trading up.