First off thank you stardock for deskscapes. I too run dual monitors. On my main monitor some dreams look amazing. Unfortunately for most dreams they look horrible on my secondary monitor. I am using a 30" and a 20" rotated into portrait mode. About the only Dream thats acceptable is Mana Shades and Blue Plasma.
As konstareal already said it would be great to be able to "disable" the dream on one monitor.
I'm guessing this is up to MS to handle this though. What Agrabren explained about Multimon is what I've been doing manually with background images for years. I'm sure I'm not the only one. If that isn't handled within Windows by now I guess my request for Dream functionality is pretty far fetched

Neil Banfield said "Regarding the performance problems with multiple display adapters : Deskscapes is designed for systems with 1 or 2 monitors on a single video adapter. If you have more than 1 card then things are going to need to be sent from card to card and that can be slow."

I can confirm this. I was running two monitors off the same card, with a second card going unused/in reserve for SLI gaming. Deskscapes were running smooth and easy this way. However, I thought to myself that it made sense to have one card on one monitor and one on the other, so I switched. Sure enough, now Deskscapes are chugging along instead of baby smooth.

So if you are a multimonitor user, two monitors on the same card will give you much better results that one monitor for each of two cards. Seems counterintuitive in some ways, but apparently sending the video data across the PCIx bus from one card to the other SUCKS.