The big VC firms are increasingly trying to do early stage angel investments to get their foot in the door, so to speak. They will likely have better advice at the early stage than they would have a few years ago because they have more experience with companies at that stage.

Also, Andreessen Horowitz added Chris Dixon (a very well known angel investor) as a general partner, so I think this speaks to their intentions of being able to help companies at an earlier stage.