As for *my* three things, I certainly gripe all the time, but it took me a while to think of anything...
1.) Storage, like everyone else. My requirements are: a.) Cheap.

, b.) Mountable, POSIX FS, not just some stupid HTTP API, c.) Reasonably fast. (In other words, just like current storage, only magically cheap!) I don't think I require anything else. In particular, I don't care if it's network or local, though obviously it
will be network, but there's no reason for me to specify. I also don't need public HTTP access, though that would probably be neat.
It would also be neat if it was accessible from the other data centers or maybe even the entire Internet (with transfer fees, obviously). Obviously that also makes mounting less practical -- though not impossible? -- but something like SFTP or rsync could work. Or, god forbid, an HTTP API. (Though this is getting into the territory of a separate, different product.) Edit: Wait. If it's *mountable*, then it's easy to rsync or SFTP to a node that has it mounted. Duh. That doesn't solve it if you want to put it in a data center you don't have a node in, though.
2.) More flexible billing. I'm cheating by listing two things, but oh well: a.) Pro-rating to less than a day. Knowing it costs a wallet-shattering $0.66 to spend three minutes testing iptables rules gives me some sticker shock. b.) Not having to pre-pay so much. I've only needed this once, but it would be nice to be able to run a reasonably large node for a few days without having to move hundreds of dollars around. Edit: I understand if you don't want to make repeatedly deploying nodes for minutes at a time *too* easy -- 15 minutes of a 512 is less than a cent, after all -- but there are ways around that. For example, having a minimum 3-6 hour commitment charged up front, then billing hourly after that.
3.) I wish the JavaScript prompts when deleting config profiles or disk images specified *which one* you are about to delete, just to double-check.
Finally, I'm going to cheat again by adding 4.) Greater transparency. You're certainly transparent *enough*, but not much more than that. You're tight-lipped as can be about future plans, and don't release the reasons for maintenance.
I feel guilty about mentioning this, since my desire for that information is pretty much entirely to satisfy my own curiosity, and as I said, you're 100% transparent *enough*. But 150% is even cooler, no? (I also feel guilty since there's a decent chance I'll unintentionally spark an argument, or that I'll be shot down for spoutin' unproven, vague nonsense.)
I understand that you don't want to make unnecessary promises about the future that you may later want to back out of, but *I* wouldn't hold it against you if you changed your mind. (And this doesn't apply to the maintenance thing at all, though for that case I do accept that *some* things need to be secret.)
Plus, the two times I've been affected by maintenance (both times for beta products, which is entirely acceptable, I hasten to add), the reasons *were* explained to me. Though the second time there was one 'sorry, that's classified' before someone more senior did discuss it. (And if you read this, Less Senior Person, I hold no ill will towards you!)
*cringe, Submit* (Yikes, this got long.)
Edit edit edit edit edit: Tweaks, nothing major.