And when I say “particle effect,” I really don’t mean actual rendered particles – I just mean the effect you get from clouds currently.
These are my suggestions:
• Sand - make sand blocks emit small same-colored puffs occassionally, in one direction, to simulate the effect of wind blowing across it.
• Water - in the blocks at the bottom of a falling column of water, make those water blocks emit cloud-like objects to simulate a real world spray effect.
That’s all! Did I miss one?
Have you been peeking at our todo list again?? 
Any other suggestions?
(Bubbling lava? Leaves falling from trees?)
/HYPE
From what I get water will be redone in future updates, can we expect realistically flowing rivers and waterfalls? Are there going to be waves in lakes/seas? Will we be able to create waterfalls/rivers/ponds on our own?
Second, it would be AH-MA-ZING if there was a falling-leaves effect. See Proteus below. A subtle effect of small colored leaf-bits drifting down from the canopy would be simply gorgeous. (Gathering and collecting on the ground an added bonus, but not essential)
Yes please!!!
May be to see some pollen flying away when a stronger gust hits lvl 4 grass 
Fog/bog areas/low clouds. Splash particles. Slight blur/fade effect when jumping through portals/warps.
Wind effects: leaves blowing from trees, grass blades being picked up from the ground, dust particles/effects from grass/dirt/stone/gravel blocks.
Weather effects: Snow, hail, tornados, whirl winds, monsunes, lightning strikes.
Lighting effects: Rays from between rocks/cracks that cover/hide gleam, flickering torches, bio-luminescant plants.
When it rains having water trickling down the sides of blocks! An ash and dust weather type. Sandstorms! Thin layers of surface material that gets cleared when you walk through it!
SANDSTORMS! That’s the one I forgot!
Dududududu. 
