First, let me just say how much I'm enjoying smartsheet. I was finally able to convince my company to begin using it internally and with our clients.
It would be tremendously helpful to be able to chat with someone who is viewing the sheet at the same time as I am. So often I'll open a sheet and get the notification that one of my clients is also viewing the sheet, but there is no way for me to communicate with them. Having a live chat window on the far right side woud be great.
The discussion feature isn't quite the same as live chat. When someone else is viewing a sheet and I add a discussion to one of their tasks, nothing on the screen will tell them that I just added a discussion to a specific row. With a chat feature, I could simply say, "Hey <client>, check out the attached form in row ## I just added. I know you've been waiting for me to provide it."
Thanks,
Artur