Hover your mouse over the button that opens up the research tree- it'll tell you what's being currently researched and how far along it is.

The mouse hover over the research button will show you the research that's queued up, and that's great, but I agree that it would be nice to see your queue on the research screen. If you're taking time away from the main game interface to look at a large window like that, it should provide you with as much information as possible about the decisions you're making in there. With the size of the window being what it is, some clever designer should be able to fit the queue in there in an efficient way.

An additional small pet peeve (just a personal feeling): does anyone else find the visual cues in the research screen less obvious than they might be? I mean, the way the buttons change to indicate "un-researchable" to "researchable" to "partly researched" to "fully researched" can be pretty subtle. That said, I'm no visual interface designer, so I don't know what I'd do to make it more obvious.