[Mooff]

Would need a additional database_query and i would have to look up a code which searchs for the first image in a thread (probably going through the vb4 files to see how it is done there) - and then some additional debug in order to not catch smileys.
Which to be honest i won't look into simply because it has no practical relevance for our forum. Which means there will arise a lot of problems i can't see or fix without extensive debugging. Article is different since we will use the slider there ourselfs.

Besides that (as an admin) i have some problems to imagine how that would run in practice, when i pull 50 threads out of our board - i end up with 48 threads without image which probably all have a similar combination of age/comments as my articles. Meaning i have no controll over what is going to show up in the slider.

That aside, if someone comes up with a database query which fetches: thread title, thread id, post count, thread date, message - and a way to find the thread image - i can easily point him in a direction where to put that code in my nivo slider widget for it to show up.

As a workaround you could promote everything out of one forum into a hidden cms-subsection. And then change the link in the slider to point at your threads (instead of articles).