The Convert section is for generation of topics for blogs in the event that you choose one of the options to have topics generated in forums.
Convert will not generate topics for private blogs, and will not generate posts for blog comments where the user specified no comments.
If you have not chosen to have topics generated from blog entries, Convert will not run.
Once you have run Convert, it will not allow you to run it again.
In Config there is a value of 50000 microsecond (0.05 second) sleep delay after each blog entry is processed. Adjust up or down as may be necessary for your server, but don't touch it unless you really understand what you're doing. The usleep(x) function won't work for Windows servers unless they are using PHP5, so Convert defaults to sleep(1), regardless of the setting in Config i.e. there will be a 1 second delay between each blog converted.
Note that the progress bar increments best under FireFox. Regrettably, for now, IE only displays the final bar when the conversion is complete, so don't be alarmed if there is a healthy delay before it completes in IE.
With the benefit of hindsight, running Convert would have resulted in comments for early blogs not being converted to posts due to the way that the "allow user comments" enhancement was set. So, the installer will set the privcomm column for all blogs to 1. This may mean you have some blogs that need to be reset to 0 after installation.
The Blog main page no longer has a small image on the right hand side of each blog title - to open a blog entry, simply click on the left half of the title bar where the cursor displays as a hand.