<"Scots" is a standardised language/dialect.  It's more conservative
<English, and has a lot of norse borrowing.  From what I can tell, Scots
<to English as Dutch is to German, maybe a bit closer.

Scots is conservative in a number of phonological aspects, others are
just as innovative as English. Morphologically Scots has also undergone
so many devlopments that is is impossible to maintain that it is more
conservative than English. It just moved into another direction.

Northumbrian dialects of English are similar to Scots because they go
back to the same base dialect in Old English, however they lack the
socio-linguistic context that the Old Anglian dialects were subjected to
in Scotland.

As I stated in an earlier posting, and I think I was misunderstood by
some, determining whether a variety is a language or a dialect cannot in
the case of closely related varieties, be made solely on linguistic
grounds, or even comprehesibility. Socio-linguistic criteria determine
whether a dialect is called a dialect or a language by its speakers or
speakers of the vis-_vis variety.

To elaborate on the comment "what about Basque" (except with "Sorbian")
of course, is a waste of time in this context, as Basque does not have a
language linguistically close enough to bring up this question in the
first place. If, for example, Basque had different standardisations on
the Fench side of the border and on the Spanish side a similar situation
could have developed - Doesn't this call for a conlang?. Linguistically
some of the Basque dialects could be considered separate languages were
the socio-linguistic circumstances different.

The perception of the population that actually speaks the
language/dialect in question is important to consider.