I'm not entirely sure what's "happened with email in 10 years"? Search-defined virtual folders?
Mark Crispin was actually pretty-damned prescient when it came to IMAP: he believed that client operations should be offloaded to a server that would have much more disk space and CPU than the client, which is exactly the model everyone reaches for today, and thereby designed a thin client protocol that had asynchronous updates baked into its core. A few years ago, he passed away: here is what I wrote at the time about his mission for IMAP and history on the project.
Really, the only thing in IMAP to actively dislike is how the thin client view requires the server to have a "dense" (here I mean the mathematics term, not from the technical spec) numbering of messages the client is modeling in its view (this is the reason opening a large mailbox via Zimbra takes forever, and why many IMAP servers have dumb global locks), but I have come up with some techniques that should allow me to handle that with minimal overhead. Otherwise, with some of the modern extensions in place (QRESYNC, for example), IMAP is pretty damned awesome.