Douglas Bowman (via MR) had a peak into Moscone West and saw an iCloud icon.   Looks familiar, no? Oh yes, we detailed this just a few months ago:

A 9to5mac reader writes in telling us he/she’s found some interesting files in Lion.  These files are labeled “MobileDocumentsFolder.icns, Mobile Documents 32.png and SidebarMobileDocumentsFolder.icns” and show new types of icons for a Cloud file system.  Clearly, this would seem to be the successor to iDisk and is probably shows a more transparent interface between the desktop and the Cloud, perhaps a little more like Dropbox. We’re also thinking there is an component as well since these are “documentsFolders”.

– here’s the new sidebar icon.

Update: In fact, it looks a lot like a mix of iDisk and iSync (which makes a lot of sense)