Meh, I think it'll turn out exactly as I said before: Trump will just toss out insults, lie and generally not answer questions. Biden will talk about policy and for the most part have a strong performance, but he'll stutter once or misstate one thing (think "millions" instead of "thousands") and THAT will be what every Trump supporter (and "concerned independents") will be talking about in here for a week afterwards.
All in all I find the debates this year more pointless than they've ever been. There aren't any undecided voters at this stage in this particular election.