Sorry about the spoilers - if some are concerned about some plot holes (IMO there isn't much to be spoilt anyway), skip this post.
Prior to watching T4, I watched T1, T2 and T3. Suffice to say, the first two were at least somewhat consistant with T3 being a downright embarrasment to the series.
I had high hopes for T4 to correct some of the mistakes that were done in T3, but I guess that would have been too good to be true. Instead, we get a movie that's perhaps just entertaining to watch, but also wastes a lot of the original plot lines. What a shame.
The idea that mankind develop self concious AI that sees their creator as their biggest enemy to then start judgement day is quite good (and perhaps to some degree realistic and plausible). I can also live with the idea that perhaps in 30 years after judgement day, machines have made more progress in technology then humans have in their entire past and create a simplistic timemachine to send back one of their terminators to "change the past". That the most logical move was to assasinate the mother of the person that leads the resistance to victory I can live with as well.
This makes for some pretty good ideas for a T4 in fact. It would have been great to bring in as to why the machines/Skynet went for this move, rather than to simply send back information regarding how the war plays out etc. There would be also lots of room to explain more on the background that would explain some things in the first two parts.
Sadly, T4 doesn't deliver on any of these fronts. When I watch T1, I also can't quite picture Kyle being the way he is portrayed in T4 either.
And why did Skynet - if Kyle is so important and the key to the past and the future - didn't they just kill Kyle when they had him locked up? If he is the key to the past and the future and that without his survivial Conner can't exist - why didn't they just kill him to ultimately kill Connor as well? Why did they have to wait for him to enter Skynet in the first place?
One might argue, that in that time frame, Skynet didn't yet have that information and thus didn't know the importance of Kyle that he would ultimately be sent back later in the war to protect S. Connor and 'seed' his future son John. But then, if they didn't yet have that information - why were they looking for him in the first place?!
This movie is a mess. They should have just made a movie showing the beginning phases of the war, perhaps the development of Terminators to hunt down humans or show how the resistant gain access to skynet to send back their protectors to the past etc.