So, it's common knowledge by now that pistons will be added in a future update. These allow the manipulation of blocks via redstone. I made a (crappy) video that should capture the essence of what I am trying to show here, and here it is:

Nice

Why do you have the pistons alternating instead of a solid row? Also, how long does cane take to grow? I think you could possibly get away with a slower clock. Maybe even an item-despawning timer to fire once every 5 minutes.

Alright, YOU try using the pistons mod and wire them all in a row (The wiring for pistons is finnicky, in that simply running a wire along all of them won't work, similar to doors). It isn't all that easy. And I know the clock is way too fast, but it will still drop sugar cane at the same rate. And using an item despawn timer for a fully automatic farm is like putting a despawn timer on a mob tower : It shows items are being dropped, which, for a fully automatic system, isn't too surprising.

It is a fairly good scratch idea.. more like realistic but.. As anything, stuff can be improved, made bigger, and/or more efficient

Yeah, it could easily be expanded, and the piston timer slowed down a bit. But otherwise, I think it's a sound design. If you wanted to, you could try wiring all the pistons, but the effort required for such a pointless benefit is dubious.