...it's a reboot in a production sense. I can honestly say I could care less how the
Enterprise looks compared to the original. Hell, the
Defiant changed appearance when they switched to CGI. Does that mean there was a timeline divergence? No, there wasn't.
The only things that get erased from my personal canon are things that are really, really,
really bad.
Threshold,
Sub Rosa,
V,
Insurrection,
A Night in Sickbay, and
And The Children Shall Lead are out of my canon for
excessively sucking. Several Ferengi episodes are borderline; but not
Spock's Brain, which is one of the funniest
Star Trek episodes ever.
It's a production reboot only, not a canon reboot. Maybe it'll change format a bit, like how when
Doctor Who came back it was in the same canon but with a new format-standalone episodes, with the occasional two or three parter and a loose season arc.
The writers and producers have stated several times that they are very interested in respecting all the canon of
Star Trek, and I see no reason to doubt them. I mean, Berman and Braga honestly said they did not care about keeping canon when it came to
Enterprise. I seriously doubt the producers of XI are lying about it not being a reboot, mostly because anyone in the past who could care less about canon were hardly subtle.
The only way XI will be non-canon in my mind is if it's awful. And, really, some of the casting choices are pushing me towards skepticism about quality. But until I see it, it is still canon.
Which is great, I'd rather have good storytelling than someone combing over scripts from 1968 to make sure their cool idea fits with some fan's notion of what's acceptable.
RDM has stated that he hated having to follow canon. They had to stop work on a ton of possibly great stories because some throw-away line of technobabble in some pre-beard TNG episode made the plot invalid.