I'm not optimistic about the next three Terminators, at all.
A big part of my complaints with the way the franchise has gone since T2 (with the partial exception of TSCC, which was pretty good, even if it's production values were a bit shaky), is how they keep pushing increasingly ludicrous Terminator variants, to the point the franchise went from a vaguely plausible future-horror, to increasingly surrealistic high-fantasy style-over substance. As far as I am concerned, anything supposedly more advanced than the T-1000 jumped the shark in terms of suspension of disbelief, both in terms of the plausibility of the technologies depicted and, more importantly, in terms of plot. A Terminator is supposed to be an infiltrator and assassin that can pass for a human and kill some of them in a surprise attack...not some self-replicating 'grey goo' nanite-infused super-weapon of mass destruction that can single-handedly fail to take over the world due to the bumbling machinations of those meddling kids and their dog Scooby-Doo too.
Of course there are plenty of other valid criticisms, but this is one of my main peeves.