The last time I checked, that channel has almost nothing to do with startups.
Nope, but it's entirely full of HN readers.
It comes and goes. It's way less serious and more off topic and casual than HN, but there are quite a few of us there.
Other than that one, I sometimes visit tech specific channels like #erlang or #chicagoboss or whatever I'm using... #postgresql is pretty good, #rubyonrails is a bit crowded these days.
#startups is a very unfriendly place with power-tripping mods. Don't go there.
There are very few people with ops in there and one of them is well known on HN (http://swombat.com/). Now that I think of it I've never seen any other op speak.