I'd love to see replaceable batteries in rechargeable models.
I also think the industry could make more use of toy to computer capability and all the potential there. Even something as simple as setting the order of a vibe's patterns (so you could turn it on and have a pulse or two, THEN go to steady, for instance) to being able to create time-based playlists (this pattern for this long, then another, etc, with perhaps a "snooze" key if you're not ready to move on yet) and your own patterns/intensities.
I think some work has been done with toys that sense motion, but I'm sure more could be done. Minna Ola's technology could be expanded into other toys, too. And non-glitchy Form 2, plzkthx. Je Joue's SaSi has potential and could be greatly expanded / empowered to fix issues and be more effective.
In the vein of the leaf vibes, I think other themes could work - like water (cloud, raindrop, icicle, bubble, etc) - I'd love to see more artistic and abstract stuff, always. I'm such a sucker for creative designs.
And one last idea that absolutely no one would want, anatomical vibrators. No, not dicks. I'd love ones like spines and hearts and other bones (you know, I think the radius has real potential). Or a uterus and vagina where the fallopian tubes and ovaries are little dual stimulator arms.
Yep. I'm crazy. Should probably sleep now.