Will there be upkeep in StarCraft II?
No, there will not be.
What will be the highest number of upgrades for the shields, armor or weapons?
Currently, the highest number of upgrades per weapon/armor/shield type will be 3, which is the same as the original StarCraft. The values of each upgrade will be determined through much balance testing.
Will the StarCraft II Editor be easy or hard to use?
Blizzard game editors have always been aimed at empowering the community to create a huge variety of fun game modes and maps. This editor will be no different.
The editor for StarCraft II will be very easy to use for new players to create their own custom maps and games. Furthermore, this editor will have many more scripting options available to players, to allow for even more player creativity in their maps beyond that seen in prior RTS titles such as Warcraft III.
Will the Zealot charge ability cause more damage on the initial attack than on all other attacks?
No, the Zealot charge will close the distance between the Zealot and its target, which will be a significant advantage in many situations, compared to a Zealot without the upgrade, but will not actually give it more attack power or an initial stronger attack.
When selecting the Phase Prisms I noticed they have a 3rd, yellow meter below their shields and health. Is this meant to represent mana or storage capacity (warp-in capacity)?
This bar represents the Phase Prisms storage capacity, as it also serves as an aerial transport unit.