No. Remote Desktop is designed for remote access, not for screen sharing. How can a user ever log out if they can't use the keyboard or mouse? This will leave countless sessions open and running in the background. You want a different product for this, not RDP.
Even if you could do this, each RDP connection opens a new, independent session to the server. Something that you do in your session will not be visible to someone else that's logged in, as your sessions would be isolated. This would defeat the purpose of using this as a presentation tool. No one could see what you were doing.
Perhaps something like WebEx or GoToMeeting might be more appropriate. You can also configure UltraVNC Server (and probably other VNC variants) to ignore remote user input.