Please include a marquee, dynamic and "hand" zoom, just like the ones you'd see in Adobe Reader or acrobat. The zoom control as it stands is limited and sort of clunky. I would really like to be able to zip around the current map a lot better. Using the mouse scroll wheel for dynamic zoom would be a neat idea. Maptools does this well, so I know you guys can implement that!
Also, for some reason, the current zoom functionality doesn't work right for me under Chrome for Linux (I know, probably not your highest priority, and probably something specific around here, but just putting my 2 cents in for something more).