I just switched to IntenseDebate, the plugin is dope, it imports your existing comments to IntenseDebate, and when a new comment is posted it also adds it to your blog’s database, so there is zero cost to try it as you can always switch back.

I enabled Facebook Connect and Twitter login, when you post a comment you will have the option to post to your wall or tweet it. It also supports OpenID, and personally I always use that when it’s supported.