I'm thinking of redoing a forum software for a 6-month-old message board.
There are plenty of features I need that are not implemented in the software I'm using. Mainly I need to integrate that board with other stuff I have, so it's not a problem with the software itself. I just need a custom-made solution.

One of the features I'm considering (since I'm going to do a custom job anyway) is having a stemmed version of the thread title appear in the file name.
I'll probably code it in a way that would preserve all existing pages, but for all new, it would have a file name like:
/post/12345/the-title-of-the-topic
or maybe
/post/12345/the-title-of-the-topic.htm

Where the 12345 is all that matters. Basically, the way everyone does it.

Is it worth doing at this point?
Do search engines pay attention to the keywords in the file name?
Would it really help rank for long-tail keywords that match the thread title (or a part of it)?
Could it actually hurt?

In other words, should I even bother?