I guess it does play a role, but probably not a major one. As /u/Hellstrike has pointed out, due to the history of the NS there has been a setback in the german identity. Especially the younger generations tend to think of themselves as europeans (I'm 25, currently studying history in Germany and politically on the far-left, so my image might me biased here).

But you can still see the regional differences on a very basic level, that is Germany being a federal republic. The single federal lands sometimes reflect their historical counterparts, sometimes they are constructs like North-Rhine-Westphalia oder Baden-Württemberg. But even here you can see the two parts the federal land consists of. Thankfully this does almost never influence political decisions, although there is still the confessional division from the cuius regio, eius religio times. Also, some regions like the Ruhrgebiet are traditionally on the political left because there live a lot of workers. The political landscape today is changing rapidly, though.

There is still a very strong regional identity. For example in Baden-Württemberg you have Swabians and Badeners. If you ask them they'll tell you they hate each others guts (not everyone, of course, I'm generalising here). But mostly it's not in a serious way and they won't stab each other if left unsupervised in a closed room.

Sometimes regional identities are re-imagined. The Kurpfalz, which is a region around Heidelberg and Mannheim, was a big deal in the middle ages and up until Napoleon due to the count palatine being an elector. But after the HRE was dismantled nobody would have identified themselves as Kurpfälzer and there are no signs that anyone ever did. But with the coming of the Romantic in the late 19th century this identity was invented and projected into the past. If you ask people today in the city of Mannheim, they'll tell you proudly that they are Kurpfälzer.

As far as I can observe, there is, at least in parts of the society, a strong interest in local history. This might be pursued by somebody investigating their ancestors or by a very passionate history teacher in a rural area. But this may be limited to people with academic background, I can't really tell.

I hope this answer isn't too confusing and I could be of help. Feel free to ask follow-ups.

The only German state that has a strong identity these days is Bavaria. Bavaria has its own political party (CSU), and Bavarian politicians of all parties are more conservative and traditional than their counterparts from other states. Bavaria is the only state where traditional (pre-industrialization) clothing is still worn for festivals and formal occasions -- the famous ''Lederhosen'' (for men) and ''Dirndls'' (for women).

The reason for this is that postunification Germany (after 1871) was dominated by Prussia -- a state that covered two thirds of Germany. Most of the traits that are or were considered typically German (punctuality, bureaucracy, militarism...) were originally Prussian traits. Bavaria was the second-largest state, so it was the natural counterpoint to Prussia, and in opposition to Prussian dominance, Bavaria preserved many of its unique traits. To this day, "Prussian" is used as an insult in Bavarian dialect.

The irony of the story is that because of two world wars, Prussia was dissolved and hardly anyone wants to identify with Prussia anymore. But Bavarian identity is still going strong.

Added to this, most other German states have rather short histories (they were created in the 20th century by mergers of smaller states or through the dissolution of Prussia), and so they can't compete with Bavaria with regards to traditionalism.

One thing I haven't seen mentioned in the thread so far, which seems as if it might be significant, is that the Western Allies after WW2 constructed the FRG with a distinct regionalised flavour - regional broadcasters rather than a single national one, and a US-style structure of federal states.

My understanding - from popular history rather than anything academic - is that this was all a deliberate attempt to reduce German nationalism.

Any comments from those more in the know than I on the matter?