I am new to this forum and saw your post and remembered that Blogger allows you to update your posts by email.
Your current posts in your discussion forum may have the ability to send an email from those posts directly to a secret email address.
Then the post will automatically appear on your Blog.
There are format issues though. Plus, if you already have a feed now, you could also have a feed for the Blog, but then you would be duplicating feeds.
My opinion would be to keep the discussion forum in place. It sounds like you have something going.
Why not start a new Blog and use it to enhance what you currently already have in place.
Offer a unique service related to what you offer now and use the Blog as a promotional portal.
More links, and more exposure.
Also, forums are a different atmosphere than Blogs and trying to turn your forum into one may be a bad idea.