As someone who played Starcraft 1 for well over ten years, and having played the new Starcraft 2 beta for over a month, I do see many many problems with the new SC.
#1. The lead designer was the lead designer of Command and Conquer - and to anyone who experienced the "RTS wars" of the late 90's/early 2000's - this is absolute blasphemy - especially for how long we waited for this game. We want THE PEOPLE WHO MADE THE ORIGINAL STARCRAFT - NOT COMMAND AND CONQUER - TO BE MAKING STARCRAFT 2.
#2. The original Starcraft experience was built off of team games and macro strategies. Starcraft 2 only shines in the 1v1 type games. This is because in the old starcraft buildings and units were considerably tougher - which meant while a battle was going on you actually had time to figure out what to build next - whether to retreat - or have time for an ally to send more units/reinforcements. In Starcraft 2 on the other hand, buildings are destroyed extremely quick with just tier 1 units - the main mining building can be destroyed with like five mutas within 20-30 seconds - and battles are over within moments - even with tons of units. This needs to change, but I believe they did this in the first place to have a "faster paced" game. The problem with making it a "faster paced" game is you lose that inherent four dimensionality of the original.
#3. You can tech too fast in SC 2(but only slightly too fast). I couldn't believe how fast I could get lair.
#4. Whereas SC 1 had straight forward units all with specific purposes and strategies(every race had one range and one melee unit in the first tier, medium specialized in second tier, heavy specialized/air in third tier), SC 2 has different kinds of of range and melee completely mixed up in every tier. Terrans have NO melee units(unless you consider the helion, with it's ginormous range/speed, as melee), protoss has ONE melee unit, and zerg has TWO melee units - this is through-out the entire game. While I know SC 1 didn't have much as far as melee units, SC 2 has like WAYYYY more range units... it seems imbalanced for range/melee mixes. Might I add, Roaches/Mauraders/Immortals are seemingly out of place because you can tech to air so quickly in this game - not to say I think these units are useless(latest patch has made Roaches very useless though).
#5. Caster effects in SC 2 are extremely small but extremely powerful and short- meaning you must have multiple casters(at least five) - and since they their spells have so little range, you have to be constantly micro-ing. THIS CASTER THING CAN BE FIXED THOUGH, it just would be nice if they had more significant graphical effects, much weaker, larger splash, and longer duration.
#6. NUKES SUCK ASS. NUKES SUCK SO BAD - THEY SUCK SOOOO SOOO MUCH this alone makes me incredibly upset at SC2. IT TAKES LIKE FOUR OR FIVE JUST TO DESTROY THEIR MAIN BUILDING - IT HAS THIS HUGE WARNING WHERE YOU CAN SEE EXACTLY WHERE THEY'RE NUKING(whereas in the original it was a tiny red dot, in this one it's like this giant target like "watch me") - and they move their miners very quickly. I guess nukes thereby will be more tactical on the battlefield, but again since battles are so quick in SC 2 I still will find it hard to properly pull off(like in SC1).
#7. Maps are very symmetrical in SC 2 - whereas in SC 1 there was a lot more "natural land-mass" feeling about them.
#8. Cliffs/chokes become useless early in the game in SC 2 - where in SC 1 they were absolutely critical - where only drops/strong air units could negate, and these required lots of teching.
Let me just say at the end of this - try playing "Huge Game Hunters" on SC 2 - and you will see how utterly UTTERLY screwed up and conked out SC 2 is compared to the original.
It turns into this cheesy, korean-based, rough at the edges, with very little four dimensionality, direction, or strategy.
If they do not completely revamp/retweek the game before launch, there will be very very critical reviews in blizzards' future.
