I might be a little late with this feedback, but I haven't been on PBE much lately. Anyway...
Currently, potions (both health and mana) are greyed out in your inventory if you have full health/mana. I find this completely counter-intuitive because, _at a glance, I cannot easily determine whether or not I have potions in my inventory_ (the greyed out icons blend in extremely well with the HUD background color).
Additionally it's difficult to tell _how many_ potions I have because both the icon and number of potions are grey, meaning I need to focus on the icon for far longer than I should need to in order to get the necessary information.
Of all the things I've had to get used to with the new HUD, this is something that I feel _cannot_ be pushed to Live as it takes a step backwards in functionality and can even affect a player's performance. I would very much like to see Live icon behavior restored before the new HUD's release: _constant red/blue icons_ for health and mana potions, respectively.
P.S. Apparently adding a poll prevents me from posting a thread. Please leave a comment stating which you prefer: dynamic grey icons or constant red/blue icons.