So I've played several games that have commentary.
Starcraft, Go(board game), and Magic the Gathering.
All three of these have had replays with commentary, and I've noticed a pattern.
There are always two commenters: the Pro, and the Scrub, for lack of better terms.
The Pro does the majority of the talking. He explains what's going on, and the Scrub's job is to chime in with good questions, so that the pro can answer them. In this way, people watching learn something and it's more interesting to them.
I think it's important to show that the smash community is friendly, energetic, and funny. That's why I really enjoy HMW's commentary. I think though, that if he had a scrub next to him asking questions, people would enjoy his commentary much more, and he'd get a lot more respect in the community.
Example:
HMW: And we've winner's semis round 2, DK vs Fox, counterpicked on FD
Scrub: So why did P1 counterpick DK and FD?
HMW: P1's confident in his DK, he knows how to combo the **** outta Foxes using the grab jump uthrow combos-oh ****, there he go, get that **** done, P1, FD's good because the Fox can't land on platforms in the air while being comboed, so DK can ****.
And then the scrub asks something else. The scrub doesn't have to be bad, just has to be able to ask good questions, so that people who are watching and don't know things keep interested.
I don't think it'd be hard to do, and I think people would enjoy his commentaries more like this.