I would guess that the module could be changed to do this, we have certainly implemented SEO within thye core Events module. However, the current forum module is now 'End of life'. I for one will be sad to see it go, Chris has put a huge amount of effort into it. That said it's replacement of Active Forums has a great following, so I look forward to that as well.
Look here for more details -
http://www.dotnetnuke.com/Resources/B...
Cheers
Roger