What did you expect? I guess I don't get why you think it would be free.
I'm quite happy with the $10/month payment. I've had a couple crashes but otherwise have been incredibly impressed with the Hulu app on my iPhone. TV shows/movies load up super fast on 3G and the quality, IMO, is superb.
I've paid $9 a month to Netflix for years, coupled with the free version of Hulu, in lieu of giving ungodly gobs of money to soul-sucking Comcast, and I',m totally fine with another $10 for more content that I can watch on my laptop, TV, and now iPhone. When Netflix gets their act together and release an iPhone app, I'm going to be thrilled.
I have seen several complaints on Twitter and elsewhere about the stability of HuluPlus, but it's been great for me.