I use 1Password on Dropbox, but is there any particular reason you can't use it with iDisk? 1Password's db "file" is really a directory and is designed to use a ton of small files for easy file-level syncing, and it notices any externally-motivated changes to the files or directory and reads the changes live. Seems like this should work just as well with iDisk as it does with Dropbox.
Mobile client (on IOS, Android). It's trivial to do this on real computers with OS access, but for me, there is a LOT of value to using 1Pass on my phone too.
What would utterly fucking rock is NFC/RFID credentials managed through 1Password too; with a dongle on my desktop, and maybe in my phone, or even a dedicated hw device.
Maybe also manage smartcard/crypto credentials (processed in HW, but this could be the admin UI to shuffle them around).
The other wishlist I have is Linux support (I'm a Linux desktop dev/sysadmin workstation holdout, with macs for mobile and office automation).
The wifi sync thing works ok, though.
It would almost be worth writing a utility to manage 1Password syncing external from 1Password.
The real solution to all of this is some kind of active agent running on each frontend which can make zero-knowledge proofs to third parties about credentials, vs. passwords, but I don't have a lot of faith the web will move to a sane authentication infrastructure anytime soon.