Used for someone who obviously has a
permanent,
high-speed connection to the forces of
weirdness in her/his
head. The
influence of this connection tends to permeate their
interactions with people, so they're seen as
highly weird.
The difference between this and hardwired to weirdness is conceptual: hardwired treats weirdness as a quality, however untreatable. Permanent uplink, on the other hand, treats weirdness as a force or an efficacious entity in itself, with its own influence over the individual, which may wax and wane.
Because of the mutability of human behavior, permanent uplink is preferred for people, while hardwired to weirdness is more appropriate to things. Of course, it depends who you know and how you know them (YMMV).