It's not so much that I think there will be another Myst game so much as the fact that I want there to be. And I haven't even finished the first one yet!
This question has been answered by Cyan Worlds (in the person of Rand Miller), and the answer is NO. However, Uru Live is ongoing, and depending on its success and Cyan Worlds' future decisions, additional content and even new games could always be written.
------------------------------------------- Fear leads to anger; anger leads to hate; hate leads to SUFFERING! - Yoda
There is a trial demo going on at Gametap until 12/31, I believe. Try going to this Gametap site & see if you can get in. (Note that this site is for PCs; if you have an Intel Mac, you need to go here instead. PPC Macs are just plain out of luck.)
------------------------------------------- Fear leads to anger; anger leads to hate; hate leads to SUFFERING! - Yoda