When I am in the forum (e.g. general discussions right now), I see a list of threads and I can see who created a thread.
Is it possible to show the person who did the last post in this thread instead? It is like this in most other forums. So when I post something and come back some time later, I want to see if somebody has posted something after me, without selecting this thread and scrolling to the bottom.

I don't think you can see who was the last person to post in a thread, but If a font colour of a thread title is white (or black in case of light scheme/theme) that means there are new posts since you have last visited it. The exception are threads with low rated OP, they're always gray.

Maybe some script-wiz can come up with something for that.

Nope, so far it's not possible to see who posted last in a partiular thread unless using some scipt perhaps as HereForTheBeer suggested. InkPanther also pretty much explained how 1 can c if the thread has new post.

The only way u dun need 2 scroll 2 the bottom is when some1 replies 2 ur post, in that case u'll received a notification under 'Account --> Forum Replies' & when u click on it u'll go automatically to that reply.