This is one of the most important thing for me with regards to the jump feature - I recall the team saying it wouldn't be implemented for getting to new places that can be reached only for jump nor would it help you in battle. However, the game as it stands in its current form feels very "2d" in its collision detection and invisible walls. The video for 2.0 showing the jumping mechanic's gameplay looks very swish - no jumping into walls that exist only on an ethereal plane - and increasing the speed of getting from A to B. Then to C. After that, to D. It looks like it might be constantly useful for travel, so I'm very glad it's looking handy.

Back to your point at hand - a lot of the foliage in the current game is physically 'transparent', however there are those larger plants and those troublesome spots which will stop you and the same goes for the fences. It's sporadic at best.
From what can tell from the gameplay video, the weeds that people are moaning about somewhat seem to be the new form of them and are physically transparent, so I'll wager a lot of these issues have been cleared up. After all, there's clearly a section where the PC jumps through a window by an NPC. My fears had indicated that such a thing would be blocked by another of these 'invisible walls'.
But, just think about it; that little ramp that a small girl wouldn't hasten to jump from near the adventurer's guild in Gridania will finally be traversable!
Huzzah!

There's one thing I do want them to add in though which I've not seen yet...
Jump Damage.