First of all, some of my ideas may have been said already, because I am not going to waste the time it would take to read all 12 pages of posts.
Second of all, I've spent quite a while researching SCII on the web and I have found out some interesting rumors that show up very often, so they may be true:
1) Water units...definitely happening.
2) Protoss pylons are mobile.
3) Two new races- Terran/Zerg Hybrids & Xel'Naga
4) New protoss ground unit (forgot name but looks really cool, I'll find the pic and post a link to it sometime.
5) Cooler graphics (I've seen an in-game pic of a scout doing barrel rolls.
6) Some new kind of terran air unit; looks like a Siege Tank-shaped Valkyrie (same pic as scout) By the way, I saw 5) & 6) on
a Blizzard site, so don't just discredit me.
7) Return of Kerrigan!
8) Something like an advanced siege tank- haven't seen a pic yet.
9) Who knows?
Third of all, some of my own little suggestions for the creators at Blizzard:
1) BETTER ZERG AIR UNITS! My God, they suck! Equivalent of a carrier or bc.
2) A zerg long range ground unit; similar to a Siege Tank or Reaver.
3) Protoss long range attack flyer- Zerg has guardians, Terran has the Yamato. The toss are left out here!
4) It would be highly cool if you could bunker up units in the building they came out of, but with a limit of how many to a building. (ex. Wraiths chill in a Starport, Marines hang out in a Barracks, Vultures are stored in a Factory) This should be purely for Terrans, and bunkered up units cannot attack. It would be like in AoEII- Conquerors.
5) Ultralisks...BURROW!
6) A new type of Templar...
7) More than just Zealots for the Protoss "infantry". Goons are cavalry. We need the equivalent of a firebat.
8) There needs to be a way to heal Protoss units without Mind Controlling a Medic. Terrans can Heal or Repair, Zerg automatically Heal, and all Protoss have is Shield Generators.
9) More to scale units. How the hell do they expect that tiny little shuttle to transport 2 Archons? Seriously.
10) They need a way for terrans to take over at least one kind of enemy unit. Toss can Mind Control, Zerg can Infest. At least have "Resocialize", to take over enemy infantry. It would have to be done in a building, and it would take time.
11) In order to do 10), it would be awesome if you could take enemies prisoner, and like, press them for information on the whereabouts of their base or something. Ghosts could read the minds of the Zerg, and there could be a torture chamber building or something.
12) MUST...INCREASE...MAX....SUPPLIES/PSI/CONTROL. Make it more of an army commanding game, like Total Annihilation. Almost infinite grouping capability, no more of that 12 to a group crap, and have at least 500 max supplies.
13) Dropship speed upgrade- Gravatic Draive and Pnuematized Carapace are great, but Dropships are too freakin slow!
14) Give Zerg and Terran a defense building like the Photon Cannon. Let it attack ground/air, and make it depend on something else in order to function.
15) It would be incredibly cool to have a zerg hero unit (1player only here, guys) that was a mix of all three (or more) races. Domination, man!
16) Two words: INFESTED PROTOSS!
17) Terran Commandoes. Like a Ghost without cloak, but with a grenade laucher or something.
18) Another cool idea: multiple attack sequences. When units attack, it's always the same. Make them have the same attacks, just make it look different sometimes. (ex. A zealot slashs sometimes, stabs sometimes)
19) Hydras must have a melee attack, if you get too close. Otherwise, what the hell are those scythes for?
Input please. I've never discussed these ideas with anyone. I want to know what the public thinks.
) for an SCV to be completed, you could control one of those 
