TBD. Incorporating user feedback and giving users options are pretty fundamental to Microsoft's standard operating procedure, so my guess is that the next public preview or beta of Win 8 will force a lot fewer changes on the user.
Really, the desktop mode of Windows 8 doesn't change all that much for power users, it just replaces the utterly broken Start Menu with a fullscreen start screen. It also makes this start screen the default environment for unsophisticated users, which is probably a reasonable move.
Aside from (IIRC) not letting you set a preference to default into the desktop mode on launch, the biggest problem with the start screen for power users was the low information density. This should be a setting, just like the default for Explorer is these giant icons and tiles for files, but you can easily switch it to use "Details" if you like to get real work done.
I think the end result for power users on traditional systems is likely to be that they deliver a desktop mode with only modest differences and a start screen that serves as a much more usable replacement for the start menu (and possibly the option to turn it back off). The start screen also provides a better replacement for some other ambient things like the desktop widgets that nobody ever sees because their apps are on top.
Meanwhile, that start screen, set to a lower information density (as was previewed), should be a pretty nifty base interface for tablet users and basic/new desktop users.
I'm sure there will still be some people up in arms, and possibly rightly so if there are some things they don't fix between now and the final release. But Win 8 has the potential to be a significant step forward without being too coercive on people who already have a good workflow in Win 7.