Now this is a feature that I’m looking forward to!
Got more than one monitor on that remote desktop? Have no fear: Vista is here! Turns out that Vista’s Terminal Service/Remote Desktop Client supports a multi-monitor setup on the remote client, making for double the remote pleasure. You’re limited to a resolution of 4096×2048 but unless you plan to watch several HDTV recordings remotely at the same time, you should be covered. On the host side, you’ll see a ginormous desktop, which comes in pretty darn handy if you’re connecting to a NASA-like computing environment. I haven’t tried this yet, but you know me: it’s just a matter of time!
Having support of multiple monitors in a remote desktop session will defiantly bring some interesting capabilities to remote control & terminal server sessions!
Source: jkOnTheRun: Vista Term Serv / Remote Desktop supports multi-monitor remote clients