I just downloaded the Labview 8.6. So here is my first impression.
It has not large improvements, so i think that is the reason it is called 8.6 and not 9.
One nice feature is the ability to make Express vis. (this was an extra toolkit i think).
This is very usefull if you have vis with many inputs which are complicated and not easy to remember. Instead of using the help window to explain each input (which is not very handy), now you can use express vis. Express vis are easy to use by other programmers too. So if a company has more than one Labview programmer, this will be a very usefull tool.
Although i think Express vis have a performance hit. If you need speed use normal vis.
One other nice tip is the ability to autowire input and output tunnel in multiple cases. You don't have to go to every case and wire it, anymore.
Something i did not like: Decorations still, can not have a name ! Everything in front panel should have an ID, and it's ref should be easy to access from block diagram.