Also, it just occurred to me that Oblivion had some really nice weather (especially after the weather mods were created), and I think the Capital Wasteland needs to see some acid rain, don't you? :)
I'd like reloading, switching weapons, and applying stimpacks or other meds/chems to cost AP points, to be more like the original games. Basically, when you perform these actions outside of VATS, your AP total takes a hit and starts to tick back up.