One unfortunate thing I noticed (alas!) only in retrospect was that frequently projects that I volunteered to work on (or had suggested) seemed to attract few other contributors. I guess "Oh, Scott's got that covered" is a nice reaction, but somehow something got lost: when I make a working prototype and/or write a complete spec, like with the Journal, networking, or "click-to-translate" (screencast coming soon!), it's because I need help. I don't want to be the only person working on these things -- I don't even need to be one of the people working on these. Please, if you think the ideas are good, pick them up and make them your own. Or just grab a piece. Where I've made prototypes, source code is available (click2trans, journal2, olpcfs1). Send me patches! Steal my projects!
One concrete request: Vino is a very nice integrated VNC server, one piece of a synchronous collaboration mechanism for Sugar. I'd love to see someone take server/vino-input.c and tweak it to map the VNC input events to a secondary mouse pointer, using MPX. Since Vino uses XDamage already (see server/vino-fb.c), another nice extension would be to have vino restrict itself to a single window (or group of windows) so we can share a specific activity/application (even if the session owner switches to a different activity or desktop).