I should imagine it should be around 5-6 dlcs some smaller than others like HF for example

I thought (and I have no evidence to back this up) that they shifted their plan from exlusively big dlcs to a kind of "whatever we give you" thing. I don't consider Dawnguard to be a big dlc, or at least on the scale of what they had in mind, but I agree that they probably are just going to count it as a big one. With Hearthfire, they seem to be showing that they are open to dish out dlc that isn't really story connected, which is what they did in Oblivion with that Mage's Tower and Castle add on. I think Dragonborn (assuming it is legit) is finally going to reveal what they wanted to do all along. I think Bethesda also realizes the time in developing these huge dlcs might have been too spaced out, and the little freebie updates weren't cutting it, so they have started throwing out these micro-dlcs to maybe appease their players during the wait.

I base this off of something I thought a forum goer said, but this obviously isn't anything official, however it makes sense. When Todd mentioned something about dlc that felt like expansion packs, I think we can all honestly say Dawnguard did not encapsulate an expansion pack. It was good, but if that was setting the bar, I wince to think of what would come next. It seems they are re-evaluating their position with some of the dlc stuff, but I think they are taking the gloves off for Dragonguard. Hopefully, they will keep giving out these smaller filler dlc, because I think these are ripe for adding functionality to the game that might have been absent, and it certainly seems like a good place to fill playerbase wants.

My conservative guess is we will get at least another big dlc past Dragonguard, and a safe bet to make is that in-between those major releases we will get dlc Hearthfire to Dawnguard sized, peppered throughout.

i thought they said there would be 5 dlc for skyrim.

Don't forget that the major factor, which determines if - and if so, how many - more DLCs will follow, is sales. As long as lots of people buy DLCs and it's profitable, I can't imagine they stop publishing content.

We do not know.