The Start of Something Good
Yes, this is the first issue with Cable. The cover can throw you for a loop because he is called a man and it looks like he is targeting the New Mutants; both couldn't be further from the truth. Regardless, this is the issue that introduced us to the son of one of the most loved X-Men.
As to the issue: it's pretty solid. A lot happens. A lot. For the most part, Louise Simonson does a good job spacing out the various story lines. The MLF is making a stand, the New Mutants are returning from Asgard, Rusty and Skids are incarcerated, and Cable is making his first appearance. Not bad for a 30-page book. My only real complaint is that the New Mutant journey is a cool one but we get very little idea as to what they are going through. Mystery guys jump out at them and fantastic vistas abound as the group returns to Midgard/Earth. It would have been pretty sweet to have devoted a whole book to the return adventure and simply show off the new talent of Rob Liefeld in a fantasy journey a la Edgar Rice Burroughs. Alas, certain ground had to be covered since X-Factor was returning at the end of this book.
As a Cable fan (and not a New Mutants devotee), jumping in at this point makes a lot of sense because Stryfe is just barely introduced and the New Mutants are getting off an adventure. The reader gets no indication of Cable's powers, nor of the fact this his arm (and more) is more than simple robot parts. Cable ends up with a pretty rich history and this first issue leaves everything in the air.