I don't think so either. However, you can right-click in the mail panel and set "show messages from" to a certain account so that views (like "All Messages/Unread" or "All Messages/Received" show only messages from that account. You can also right-click on the mail panel toolbar, goto customize and add the account selector drop-down to do the same thing. Just note that it resets to "all" on startup. You can also put account's in groups and select a group to show.
That method works best with POP, but it'll still work with IMAP. It will just show messages from all IMAP folders (that aren't specially set on the "IMAP" tab in the account's properties). But, that's great for reading messages, especially if you use "Unread". It takes some getting use to though if you're used to dealing with IMAP folders directly.