For my really long response, try here

Many Variables

To save time and trouble, though, I can sum up by giving my three opinions right here.

1. Flying worlds will probably be needed
because the trip to the stars will not
be a short one and, as Gary has
done such a good job of explaining,
radiation will prevent hibernauts
from reaching their destination intact.
Also, if human expansion into the
Solar System is gradual and 'natural'
as humans go increasingly farther out
in search of resources to sustain
their interplanetary civilization, they
should eventually find themselves
inhabiting small worlds at the edge of
the Solar System, anyway. But once
traveling worlds exist and their
inhabitants are freed of the need to
live in an expensive inefficient
gravity well, there may not be much
reason to ever leave such places,
especially if Earth twins are rare and
if terraforming is very difficult. Once
aboard such a big starship, why ever
leave it behind? Why decelerate it,
accelerate it, decelerate it,
accelerate it? The ship remains on
the move essentially forever. Smaller
manned and unmanned scout ships
might leave it and touch new worlds,
but the mother ship continues the
Grand Tour.

2. Humans may not go at all. Or, if they
go, they may not lead the expedition.
Those who do go may be human-like,
may share traits and characteristics
with us, their ancestors. But I would
expect them to be the result of both
our biology and our technology. Some
might be half-animal half-machine,
perhaps not terribly bright, and geared
toward repetitive work that would
drive a more complex mind insane with
boredom. A few might be super-
intelligent beings, mostly technological,
incorporating AI. And all might be
linked to produce a gestalt, an
intelligence even greater than its AI
components. If humans are around,
they may in a sense be 'volunteers.'
Their cyborg AI successors invited
them and they opted to go. Their
society within the larger AI gestalt
might constitute a kind of nature
preserve or reservation. A symbiosis
between the two species might exist
whereby the AI gestalt easily
satisfies the needs and desires of
their human companions, while the
humans perform tasks not well-suited
to the AI gestalt, or in situations
where AI resources are better
allocated elsewhere. And even these
'human' companions of the AI gestalt
might not be exactly human, though
they would be recognizable to us.
If they have been genetically
engineered, they could be a breed
of biologically and technologically
enhanced humans. And they would
probably be able to 'jack in' to tap
into the vast resources of the AI
gestalt itself.

3. Such traveling worlds, if piloted and
crewed by some version of the AI
gestalt, might 'colonize' worlds by
creating or modifying human life so
that it can exist within biospheres on
worlds that are not very Earth-like.
In such a way, some worlds might be
selectively colonized by AI and humans
in line with some larger strategy and
agenda. Or not. But if such
colonization were to take place, then
humanity would not merely have one
successor, but several species who
could claim descent from humanity.
The giant starship(s), though, would
never stop, continuing a great and
endless journey of exploration until
transformed by the next great event
in the evolution of animal and machine.