There's a charmingly amusing scene in this episode where The Doctor has to explain to a government minister why the War Machine that threatened to attack at the end of Episode Three came up lame at the start of Episode Four. The reason? The War Machine was a computer, and that computer hadn't been completely programmed yet. Whoa, whoa, whoa....what is this gibberish that you're talking about, Doctor?, the minister asks (paraphrased, naturally). Archive footage of what was then current technology being marveled at never ceases to amuse me, and that scene falls right into that category. With Doctor Who's first foray into the here and now (there and then), it means that it instantly becomes dated. It's mildly beneficial that the stories of the UNIT era was supposedly set a few years in the future, because then manned Mars missions and giant, army issued laser guns were so far fetched for the present day that the viewer could only surmise that the story they were watching was set in a weird and wonderful fantasy world of the unknown - the future.
Having said that, The War Machines bears so many hallmarks of what's to come that I'm willing to not only look over the dated aspects of the story, but be amused by them as an interesting snapshot of the world as it was in 1966. I also enjoyed The Doctor's role in capturing a War Machine, reprogramming it (there's that word again), and sending it to kill Krimpton. Oh, and WOTAN, too. In a further flash forward of what's to come, The Doctor vanishes shortly after the super computer is defeated, a la the Lone Ranger, just as The Second Doctor was wont to do in the stories to come.
At the end, of course, Dodo pretty much sends a text message that she is leaving in the worst companion departure scene ever. Let's hope Ben and Polly fare better.