I have used soprano baroque recorders for students aged 8-10 as a "pre-band" instrument. I find that most students enjoy practicing note-reading, and the average student is able to progress reasonably far in two years of study. I find that students who can master at least the first octave of the instrument progress very quickly on clarinet or saxophone in their next year after playing recorder. I suspect it's because there are so many similarities (the basic fingerings, breathing, etc.).
I have also noticed that beginner flute players struggle tremendously because it's so much harder to produce a tone on a flute. I know that playing a single-reed instrument is obviously different than a fipple flute but it's a similar shape and size and students seem to adapt quickly. The concert ("band") flute is quite different and in my experience, harder. Flute students at this age (10 or 11 years) seem to more frequently lose interest as their reed-playing classmates advance beyond their skill level.
I'd like to be able to give all the students a chance to learn some rudimentary skills for flute playing, too.
I'm curious... does there exist a simple instrument that could do for the flute what the recorder does for clarinet and saxophone? Is there such thing as a "transverse recorder," say?