I keep posting feature requests for Disqus here, or for anyone who might be developing a competitive product. 

Wouldn't it be nice if you could set a maximum length for comments?  

We seem to like a limit in Twitter (though I wish it were more than 140, personally). 

Why not have a sysop-settable limit.  

I'd start with a 1000 character limit.  

If you need more than 1000 characters, you should be writing a blog post, not a comment. 

What do you think? 

I think we need a more hackable comment system, btw, so if we get ideas for features we don't have to wait, possibly a very long time. How about an open source commenting system?