Siemens is big in Niedersachsen (e.g. Braunschweig) so it's more about East/West divide.
So when a big (and presumably well-paying) company is going to create lots of jobs in the country, whether this is in an eastern or a western state is indeed a very important question.
EDIT: Please note though, that it's somewhat controversial how relevant the divide really is these days. Some will tell you it's 90% in peoples heads, others will tell you that there's still a long way to go before we can really call the german reunification complete.
Politically, east-west is obviously dominant.