I would say the IR/MCE issue that alentsa was asking about would be near the top of my interest list as I intend to install Vista Premium and use the MCE features, but in XP Pro (non MCE, but using HIP library) I get zero response from the IR except the flashing blue reception light.
Second I think the "display is idle" message and restarting the Display Wizard in LCDStudio is priority to me. I checked all my powersaving settings, turned all USB onboard hubs and drivers to disable power control, and I still have to restart the Display Wizard and reload the Playlist several times over the past 3-5 days. Not crippling, but I have used LCDStudio on my G-15, so I think it has something to do with the interaction between the GX and the Application, or the GX itself, rather then solely LCDStudio.
Third, I am interested in the progress on dynamic color control like in the DriverCore Test Visualization in Winamp. If that can be implemented in LCDStudio, it should be tied to data items in color scrolling, or picking a group of color to scroll instead of the whole rainbow (like, red/blue only, or Green/Blue only, etc.).
Lastly, I eagerly await the fan/light/GPO add-on, and will be watching closely for it's developement/arrival, etc.
For those of us "early adopters"

I have a LAN showing for 500 people at the end of August, and having some sense of what I can expect to display to the viewers would be immensely comforting.
