Unfortunately, it has to be said (I mean it REALLY HAS TO BE SAID), but I am just hoping with all my might that honey trees are irradicated from all future pokemon games including HGSS.
I don't want to see jhoto with the same layout either. It was by far my favourite region but I think if it's kept the same with cities in the same places and buildings where they usually are, experienced trainers will pass the game with no sense of challenge. I think the cities should have:
a different look with buildings in different locations
or
cities located in different areas of jhoto (or when reached) kanto
or
instead of going from one city to another in the same order, I think the order of which you visit cities should be totally altered.
I don't wanna see a red garados either... something new.
[I hope they keep the cloning glitch though
]