Excellent article! I would like to keep receiving CDs from the fan club, as long as the content is good. I'm not really interested in posters, signed stuff, key chains, and other trinkets that some fan clubs offer.
I agree with pretty much all of your picks... I'd love Clockwork Orange, Songs of Ascent, Passengers 2, and some great live stuff. A Bono version of "The Wanderer" has been on my wish list for years. I LOVE the band version from the Johnny Cash tribute concert (you can download the audio from U2Start).
Demos and session outtakes would also be great... not just from the early years, but from the recent albums as well. Even just alternate versions of album tracks, similar to the Kindergarten disc in the AB boxed set. I love that one. For example, it would be great to hear the early versions of HMTMKMKM and Wake Up Dead Man that were originally intended for Zooropa.
As for live material, I think the U2360 CDs have set the standard. I'd like to see them do something similar with each tour they've done. Rather than releasing a full concert, I'd like 2CD versions of the highlights, the best performances in different cities, from each tour. I'm sure these could be assembled fairly easily from tours going all the way back to the TUF era, and maybe even earlier.
And I know I'm in the minority here, but I wouldn't mind another remix album--if done right. I think Artificial Horizon was great for what it was, even though some of it was previously released. With the right track list and sequencing, and the right remixers, I think another good U2 remix CD would be possible.
One thing I DON'T want: an updated/re-recorded/"finished" Pop album. Thankfully the band seems to have abandoned this idea over the past decade or so.