I haven't played any of the Fallout games yet (sadly), but a friend who's been an avid fan and player since the first game had this to share with me after reading books for the franchise:
"Well, mainly the subjects of technology and aliens. Like, there's space travel. In Mass Effect, people are able to get anywhere within hours thanks to the mass relays left behind by the reapers. In Halo, mankind had to develop their own method of travel (which wasn't accomplished until the 24th century, 200 years after humanity in Mass Effect was rocketed forward by the Mars discovery). They use this "Shaw-Fujikawa" drive in order to slip through space-time and such, and while it's not as efficient as a mass relay (depending on the distance between worlds, a ship in Halo can take anywhere from a few hours to several months to reach its destination), it's still humanity's most important advancement. Then there's the interesting subject of AI, which is pretty much polar opposite of AI in Mass Effect.
Synthetics are widely used in Halo, and, in order to ensure they don't turn on people, they're actually made to mimic human beings as close as possible (this is why Cortana in Halo shows so much more emotion and personality than Legion in Mass Effect). For example, having the ability to have conversations with humans or other AI. They also each have their own avatar to distinguish them from each other. And, each AI is actually created from the mind of an existing human, so, in a sense, they're kind of like artificial clones of another person. They're an invaluable part of human society and are generally trusted by everyone, but it is possible they can become depressed and even turn on people, a state known in-universe as "rampancy." But generally this doesn't happen often.
Then there's the Forerunners, the Halo equivalent of the Protheans. And the Covenant, the collective of alien races that worships them and hope to ascend to godhood by unlocking the secrets of the Halo rings the Forerunners left behind."
Now, again, me not having played the games yet means I know very little about the lore, but the things he noticed had many interesting comparisons, points, and polar ideals. (I found it interesting, I guess.)
So, perhaps in a way, yes. I'd love to see just what the new Fallout games would have to immense players in. :V