Apple will take money from pro users but doesn't care about them at all from a strategic perspective. See Final Cut Pro X and the total lack of consideration for businesses running the previous version. No, Mac OS X won't suddenly drop support for multiple monitors, but I don't expect Apple to devote much time to making new features work well with them.
Because they fudged support in the initial release of Lion? Get real. If you're so effected by it, downgrade until there's an update that fixes it. But don't assume that the workstation of choice among graphic artists is going to completely drop multi-monitor support just because it isn't exactly how you want it right at release.